{"id":33795,"date":"2026-09-29T14:28:29","date_gmt":"2026-09-29T07:28:29","guid":{"rendered":"https:\/\/etest.edu.vn\/?p=33795"},"modified":"2026-09-29T14:28:29","modified_gmt":"2026-09-29T07:28:29","slug":"phuong-trinh-bac-nhat-hai-an-trong-sat-cach-giai-nhan-dien-va-bai-tap-minh-hoa","status":"publish","type":"post","link":"https:\/\/etest.edu.vn\/en\/phuong-trinh-bac-nhat-hai-an-trong-sat-cach-giai-nhan-dien-va-bai-tap-minh-hoa\/","title":{"rendered":"Ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n trong SAT: C\u00e1ch gi\u1ea3i, nh\u1eadn di\u1ec7n v\u00e0 b\u00e0i t\u1eadp minh h\u1ecda"},"content":{"rendered":"<p><b>Ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n<\/b><span style=\"font-weight: 400;\"> l\u00e0 m\u1ed9t ch\u1ee7 \u0111\u1ec1 quan tr\u1ecdng trong <\/span><a href=\"https:\/\/etest.edu.vn\/en\/khoa-hoc\/luyen-thi-sat\/\"><b>SAT<\/b><\/a><b> Math<\/b><span style=\"font-weight: 400;\">, \u0111\u1eb7c bi\u1ec7t khi \u0111\u1ec1 b\u00e0i y\u00eau c\u1ea7u h\u1ecdc sinh l\u1eadp ph\u01b0\u01a1ng tr\u00ecnh t\u1eeb d\u1eef ki\u1ec7n th\u1ef1c t\u1ebf, x\u00e1c \u0111\u1ecbnh m\u1ed9t c\u1eb7p nghi\u1ec7m ho\u1eb7c k\u1ebft h\u1ee3p hai ph\u01b0\u01a1ng tr\u00ecnh \u0111\u1ec3 t\u00ecm gi\u00e1 tr\u1ecb c\u1ee7a c\u00e1c bi\u1ebfn. N\u1ebfu n\u1eafm \u0111\u01b0\u1ee3c c\u00e1ch nh\u1eadn di\u1ec7n v\u00e0 x\u1eed l\u00fd \u0111\u00fang, h\u1ecdc sinh c\u00f3 th\u1ec3 gi\u1ea3i nhanh nhi\u1ec1u c\u00e2u h\u1ecfi thu\u1ed9c nh\u00f3m <\/span><b>Algebra<\/b><span style=\"font-weight: 400;\"> and <\/span><b>Problem-Solving and Data Analysis<\/b><span style=\"font-weight: 400;\">.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Trong b\u00e0i vi\u1ebft n\u00e0y, h\u00e3y c\u00f9ng ETEST t\u00ecm hi\u1ec3u <\/span><b>ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n l\u00e0 g\u00ec, c\u00e1ch gi\u1ea3i trong SAT v\u00e0 nh\u1eefng d\u1ea1ng b\u00e0i th\u01b0\u1eddng g\u1eb7p<\/b><span style=\"font-weight: 400;\"> v\u00e0 b\u00e0i t\u1eadp minh h\u1ecda.<\/span><\/p>\n<figure id=\"attachment_33796\" aria-describedby=\"caption-attachment-33796\" style=\"width: 711px\" class=\"wp-caption aligncenter\"><img decoding=\"async\" class=\"wp-image-33796 size-medium\" src=\"https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-44-711x400.jpg\" alt=\"\" width=\"711\" height=\"400\" srcset=\"https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-44-711x400.jpg 711w, https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-44-1400x788.jpg 1400w, https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-44-768x432.jpg 768w, https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-44-1536x864.jpg 1536w, https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-44-18x10.jpg 18w, https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-44.jpg 1920w\" sizes=\"(max-width: 711px) 100vw, 711px\" \/><figcaption id=\"caption-attachment-33796\" class=\"wp-caption-text\">Ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n trong SAT: C\u00e1ch gi\u1ea3i, nh\u1eadn di\u1ec7n v\u00e0 b\u00e0i t\u1eadp minh h\u1ecda<\/figcaption><\/figure>\n<h2><b>Ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n l\u00e0 g\u00ec?<\/b><\/h2>\n<p><span style=\"font-weight: 400;\">Ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n th\u01b0\u1eddng c\u00f3 d\u1ea1ng:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">ax+by=c\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">In there:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">x,yx, y l\u00e0 hai \u1ea9n.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">a,b,ca, b, c l\u00e0 c\u00e1c h\u1eb1ng s\u1ed1.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">aa v\u00e0 bb kh\u00f4ng \u0111\u1ed3ng th\u1eddi b\u1eb1ng 0.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Kh\u00f4ng c\u00f3 c\u00e1c s\u1ed1 m\u0169 nh\u01b0 <\/span><i><span style=\"font-weight: 400;\">x\u00b2, y\u00b2 <\/span><\/i><span style=\"font-weight: 400;\">\u00a0ho\u1eb7c t\u00edch<\/span><i><span style=\"font-weight: 400;\"> xy<\/span><\/i><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">V\u00ed d\u1ee5: 2x+3y=12 l\u00e0 ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Ng\u01b0\u1ee3c l\u1ea1i:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">x2+y=10\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">kh\u00f4ng ph\u1ea3i ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n v\u00ec xx c\u00f3 s\u1ed1 m\u0169 2.\u00a0<\/span><\/p>\n<h3><b>M\u1ed9t ph\u01b0\u01a1ng tr\u00ecnh c\u00f3 nhi\u1ec1u nghi\u1ec7m<\/b><\/h3>\n<p><span style=\"font-weight: 400;\">Kh\u00e1c v\u1edbi ph\u01b0\u01a1ng tr\u00ecnh m\u1ed9t \u1ea9n, m\u1ed9t ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n th\u01b0\u1eddng c\u00f3 <\/span><b>v\u00f4 s\u1ed1 c\u1eb7p nghi\u1ec7m<\/b><span style=\"font-weight: 400;\">.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">For example:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">x+y=10\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">M\u1ed9t s\u1ed1 nghi\u1ec7m c\u00f3 th\u1ec3 l\u00e0: (2,8),(4,6),(7,3)\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Mi\u1ec5n l\u00e0 gi\u00e1 tr\u1ecb c\u1ee7a xx v\u00e0 yy th\u1ecfa m\u00e3n ph\u01b0\u01a1ng tr\u00ecnh.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u0110\u00e2y l\u00e0 \u0111i\u1ec3m h\u1ecdc sinh c\u1ea7n l\u01b0u \u00fd khi l\u00e0m SAT: <\/span><b>m\u1ed9t ph\u01b0\u01a1ng tr\u00ecnh hai \u1ea9n ch\u01b0a \u0111\u1ee7 \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh duy nh\u1ea5t c\u1ea3 hai bi\u1ebfn<\/b><span style=\"font-weight: 400;\">.<\/span><\/p>\n<h2><b>Ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n xu\u1ea5t hi\u1ec7n nh\u01b0 th\u1ebf n\u00e0o trong SAT?<\/b><\/h2>\n<p><span style=\"font-weight: 400;\">In <\/span><a href=\"https:\/\/etest.edu.vn\/en\/digital-sat\/\"><span style=\"font-weight: 400;\">Digital SAT<\/span><\/a><span style=\"font-weight: 400;\">, d\u1ea1ng to\u00e1n n\u00e0y th\u01b0\u1eddng kh\u00f4ng \u0111\u01b0\u1ee3c h\u1ecfi \u0111\u01a1n gi\u1ea3n theo ki\u1ec3u \u201cgi\u1ea3i ph\u01b0\u01a1ng tr\u00ecnh\u201d. Thay v\u00e0o \u0111\u00f3, \u0111\u1ec1 b\u00e0i c\u00f3 th\u1ec3 \u0111\u1eb7t trong m\u1ed9t t\u00ecnh hu\u1ed1ng th\u1ef1c t\u1ebf v\u00e0 y\u00eau c\u1ea7u h\u1ecdc sinh x\u00e2y d\u1ef1ng ho\u1eb7c ph\u00e2n t\u00edch m\u00f4 h\u00ecnh to\u00e1n h\u1ecdc.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">M\u1ed9t s\u1ed1 d\u1ea1ng th\u01b0\u1eddng g\u1eb7p g\u1ed3m:<\/span><\/p>\n<ol>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">T\u00ecm m\u1ed9t gi\u00e1 tr\u1ecb khi bi\u1ebft gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ebfn c\u00f2n l\u1ea1i.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">X\u00e1c \u0111\u1ecbnh ph\u01b0\u01a1ng tr\u00ecnh ph\u00f9 h\u1ee3p v\u1edbi t\u00ecnh hu\u1ed1ng.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">T\u00ecm giao \u0111i\u1ec3m c\u1ee7a hai \u0111\u01b0\u1eddng th\u1eb3ng.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Gi\u1ea3i h\u1ec7 ph\u01b0\u01a1ng tr\u00ecnh.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Ph\u00e2n t\u00edch b\u1ea3ng ho\u1eb7c \u0111\u1ed3 th\u1ecb.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">X\u00e1c \u0111\u1ecbnh s\u1ed1 l\u01b0\u1ee3ng ho\u1eb7c chi ph\u00ed trong b\u00e0i to\u00e1n th\u1ef1c t\u1ebf.<\/span><\/li>\n<\/ol>\n<p><span style=\"font-weight: 400;\">V\u00ec v\u1eady, k\u1ef9 n\u0103ng quan tr\u1ecdng kh\u00f4ng ch\u1ec9 l\u00e0 t\u00ednh to\u00e1n m\u00e0 c\u00f2n l\u00e0 <\/span><b>d\u1ecbch th\u00f4ng tin t\u1eeb \u0111\u1ec1 b\u00e0i th\u00e0nh ph\u01b0\u01a1ng tr\u00ecnh<\/b><span style=\"font-weight: 400;\">.<\/span><\/p>\n<figure id=\"attachment_33797\" aria-describedby=\"caption-attachment-33797\" style=\"width: 711px\" class=\"wp-caption aligncenter\"><img decoding=\"async\" class=\"wp-image-33797 size-medium\" src=\"https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-1-25-711x400.jpg\" alt=\"\" width=\"711\" height=\"400\" srcset=\"https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-1-25-711x400.jpg 711w, https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-1-25-1400x788.jpg 1400w, https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-1-25-768x432.jpg 768w, https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-1-25-1536x864.jpg 1536w, https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-1-25-18x10.jpg 18w, https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-1-25.jpg 1920w\" sizes=\"(max-width: 711px) 100vw, 711px\" \/><figcaption id=\"caption-attachment-33797\" class=\"wp-caption-text\">Ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n xu\u1ea5t hi\u1ec7n nh\u01b0 th\u1ebf n\u00e0o trong SAT?<\/figcaption><\/figure>\n<h1><b>C\u00e1ch gi\u1ea3i ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n trong SAT<\/b><\/h1>\n<h2><b>C\u00e1ch 1: Bi\u1ec3u di\u1ec5n m\u1ed9t \u1ea9n theo \u1ea9n c\u00f2n l\u1ea1i<\/b><\/h2>\n<p><span style=\"font-weight: 400;\">X\u00e9t ph\u01b0\u01a1ng tr\u00ecnh:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">3x+2y=12\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">N\u1ebfu c\u1ea7n t\u00ecm y, ta chuy\u1ec3n 3x sang v\u1ebf ph\u1ea3i:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">2y=12\u22123x\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Sau \u0111\u00f3: y= 6 &#8211; 3\/2x<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Nh\u01b0 v\u1eady, ph\u01b0\u01a1ng tr\u00ecnh \u0111\u00e3 \u0111\u01b0\u1ee3c vi\u1ebft d\u01b0\u1edbi d\u1ea1ng: y=mx+b\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">In there:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">m=\u22123\/2 l\u00e0 h\u1ec7 s\u1ed1 g\u00f3c.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">b =6 l\u00e0 tung \u0111\u1ed9 g\u1ed1c.<\/span><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">D\u1ea1ng n\u00e0y \u0111\u1eb7c bi\u1ec7t h\u1eefu \u00edch khi SAT cho <\/span><b>\u0111\u1ed3 th\u1ecb \u0111\u01b0\u1eddng th\u1eb3ng<\/b><span style=\"font-weight: 400;\">.<\/span><\/p>\n<h2><b>C\u00e1ch 2: T\u00ecm gi\u00e1 tr\u1ecb c\u1ee7a m\u1ed9t bi\u1ebfn khi bi\u1ebft bi\u1ebfn c\u00f2n l\u1ea1i<\/b><\/h2>\n<p><span style=\"font-weight: 400;\">V\u00ed d\u1ee5: 4x+3y=24<\/span><\/p>\n<p><span style=\"font-weight: 400;\">N\u1ebfu x =3, ta c\u00f3:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">4(3)+3y=24\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">12+3y=24\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">3y=12\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">y=4\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">V\u1eady m\u1ed9t nghi\u1ec7m c\u1ee7a ph\u01b0\u01a1ng tr\u00ecnh l\u00e0: (3,4)\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">N\u1ebfu \u0111\u1ec1 \u0111\u00e3 cho m\u1ed9t gi\u00e1 tr\u1ecb c\u1ee7a xx ho\u1eb7c yy, <\/span><b>thay tr\u1ef1c ti\u1ebfp v\u00e0o ph\u01b0\u01a1ng tr\u00ecnh<\/b><span style=\"font-weight: 400;\"> th\u01b0\u1eddng nhanh h\u01a1n vi\u1ec7c bi\u1ebfn \u0111\u1ed5i to\u00e0n b\u1ed9 ph\u01b0\u01a1ng tr\u00ecnh.\u00a0<\/span><\/p>\n<h1><b>H\u1ec7 ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n<\/b><\/h1>\n<p><span style=\"font-weight: 400;\">M\u1ed9t d\u1ea1ng quan tr\u1ecdng h\u01a1n l\u00e0 <\/span><b>h\u1ec7 hai ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n<\/b><span style=\"font-weight: 400;\">:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">{ax+by=c<\/span><\/p>\n<p><span style=\"font-weight: 400;\">{dx + ey =f<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400;\">M\u1ee5c ti\u00eau l\u00e0 t\u00ecm c\u1eb7p gi\u00e1 tr\u1ecb (x,y)(x,y) th\u1ecfa m\u00e3n <\/span><b>c\u1ea3 hai ph\u01b0\u01a1ng tr\u00ecnh<\/b><span style=\"font-weight: 400;\">.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">C\u00f3 ba c\u00e1ch ph\u1ed5 bi\u1ebfn:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Ph\u01b0\u01a1ng ph\u00e1p th\u1ebf.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Ph\u01b0\u01a1ng ph\u00e1p c\u1ed9ng \u0111\u1ea1i s\u1ed1.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">S\u1eed d\u1ee5ng \u0111\u1ed3 th\u1ecb.<\/span><\/li>\n<\/ul>\n<h1><b>Hi\u1ec3u h\u1ec7 ph\u01b0\u01a1ng tr\u00ecnh th\u00f4ng qua \u0111\u1ed3 th\u1ecb<\/b><\/h1>\n<p><span style=\"font-weight: 400;\">M\u1ed7i ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c bi\u1ec3u di\u1ec5n b\u1eb1ng <\/span><b>m\u1ed9t \u0111\u01b0\u1eddng th\u1eb3ng tr\u00ean m\u1eb7t ph\u1eb3ng t\u1ecda \u0111\u1ed9<\/b><span style=\"font-weight: 400;\">.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">For example:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">y=x+2 v\u00e0 y=\u2212x+6\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Khi bi\u1ec3u di\u1ec5n tr\u00ean c\u00f9ng m\u1ed9t h\u1ec7 tr\u1ee5c t\u1ecda \u0111\u1ed9, hai \u0111\u01b0\u1eddng th\u1eb3ng giao nhau t\u1ea1i m\u1ed9t \u0111i\u1ec3m.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Gi\u1ea3i h\u1ec7 ph\u01b0\u01a1ng tr\u00ecnh ch\u00ednh l\u00e0 t\u00ecm <\/span><b>t\u1ecda \u0111\u1ed9 giao \u0111i\u1ec3m<\/b><span style=\"font-weight: 400;\"> \u0111\u00f3.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">V\u1edbi h\u1ec7 tr\u00ean:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">x+2=\u2212x+6\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">2x=4\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">x=2\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Suy ra: y = 4<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Giao \u0111i\u1ec3m l\u00e0: (2,4)\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u0110i\u1ec1u n\u00e0y gi\u00fap h\u1ecdc sinh hi\u1ec3u b\u1ea3n ch\u1ea5t c\u1ee7a h\u1ec7 ph\u01b0\u01a1ng tr\u00ecnh thay v\u00ec ch\u1ec9 ghi nh\u1edb c\u00e1c b\u01b0\u1edbc t\u00ednh to\u00e1n.\u00a0<\/span><\/p>\n<h1><b>Ba tr\u01b0\u1eddng h\u1ee3p c\u1ea7n nh\u1edb khi gi\u1ea3i h\u1ec7 ph\u01b0\u01a1ng tr\u00ecnh<\/b><\/h1>\n<p><span style=\"font-weight: 400;\">SAT c\u00f3 th\u1ec3 ki\u1ec3m tra kh\u1ea3 n\u0103ng nh\u1eadn bi\u1ebft ba tr\u01b0\u1eddng h\u1ee3p sau.<\/span><\/p>\n<h3><b>1. C\u00f3 m\u1ed9t nghi\u1ec7m duy nh\u1ea5t<\/b><\/h3>\n<p><span style=\"font-weight: 400;\">Hai \u0111\u01b0\u1eddng th\u1eb3ng c\u1eaft nhau t\u1ea1i m\u1ed9t \u0111i\u1ec3m.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">V\u00ed d\u1ee5: y=2x+1\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0y=\u2212x+7\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u2192 C\u00f3 <\/span><b>m\u1ed9t nghi\u1ec7m<\/b><span style=\"font-weight: 400;\">.\u00a0<\/span><\/p>\n<h3><b>2. Kh\u00f4ng c\u00f3 nghi\u1ec7m<\/b><\/h3>\n<p><span style=\"font-weight: 400;\">Hai \u0111\u01b0\u1eddng th\u1eb3ng song song v\u00e0 kh\u00e1c nhau.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">V\u00ed d\u1ee5: y=2x+1\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0y=2x+5\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Hai \u0111\u01b0\u1eddng c\u00f3 c\u00f9ng h\u1ec7 s\u1ed1 g\u00f3c nh\u01b0ng kh\u00e1c tung \u0111\u1ed9 g\u1ed1c.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u2192 <\/span><b>Kh\u00f4ng c\u00f3 nghi\u1ec7m chung.<\/b><\/p>\n<h3><b>3. V\u00f4 s\u1ed1 nghi\u1ec7m<\/b><\/h3>\n<p><span style=\"font-weight: 400;\">Hai ph\u01b0\u01a1ng tr\u00ecnh th\u1ef1c ch\u1ea5t bi\u1ec3u di\u1ec5n c\u00f9ng m\u1ed9t \u0111\u01b0\u1eddng th\u1eb3ng.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">V\u00ed d\u1ee5: 2x+4y=8 v\u00e0 x+2y=4\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Ph\u01b0\u01a1ng tr\u00ecnh th\u1ee9 nh\u1ea5t ch\u1ec9 l\u00e0 ph\u01b0\u01a1ng tr\u00ecnh th\u1ee9 hai nh\u00e2n v\u1edbi 2.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u2192 <\/span><b>V\u00f4 s\u1ed1 nghi\u1ec7m.<\/b><\/p>\n<h1><b>B\u00e0i t\u1eadp minh h\u1ecda SAT Math<\/b><\/h1>\n<h2><b>B\u00e0i 1: T\u00ecm gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ebfn<\/b><\/h2>\n<p><span style=\"font-weight: 400;\">Cho:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">5x+2y=18\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">N\u1ebfu x =2, gi\u00e1 tr\u1ecb c\u1ee7a y b\u1eb1ng bao nhi\u00eau?\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">L\u1eddi gi\u1ea3i:\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">5(2)+2y=18\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">10+2y=18\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">2y=8\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">y=4\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u0110\u00e1p \u00e1n: 4\u00a0<\/span><\/p>\n<p><b>B\u00e0i 2: Gi\u1ea3i h\u1ec7 ph\u01b0\u01a1ng tr\u00ecnh\u00a0<\/b><\/p>\n<p><span style=\"font-weight: 400;\">Cho:<\/span> <span style=\"font-weight: 400;\">x + y = 13<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0x &#8211; y = 5<\/span><\/p>\n<p><span style=\"font-weight: 400;\">C\u1ed9ng hai ph\u01b0\u01a1ng tr\u00ecnh: 2x = 18<\/span><\/p>\n<p><span style=\"font-weight: 400;\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0x = 9<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Thay v\u00e0o:\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">9+y=13\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">y=4\u00a0<\/span><\/p>\n<p><b>Answer: <\/b><span style=\"font-weight: 400;\">x = 9, y = 4.<\/span><\/p>\n<h2><b>B\u00e0i 3: B\u00e0i to\u00e1n th\u1ef1c t\u1ebf<\/b><\/h2>\n<p><span style=\"font-weight: 400;\">M\u1ed9t r\u1ea1p chi\u1ebfu phim b\u00e1n t\u1ed5ng c\u1ed9ng 120 v\u00e9 ng\u01b0\u1eddi l\u1edbn v\u00e0 tr\u1ebb em. V\u00e9 ng\u01b0\u1eddi l\u1edbn c\u00f3 gi\u00e1 12 USD, v\u00e9 tr\u1ebb em c\u00f3 gi\u00e1 8 USD. T\u1ed5ng doanh thu l\u00e0 1.200 USD.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">G\u1ecdi:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">x: s\u1ed1 v\u00e9 ng\u01b0\u1eddi l\u1edbn.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">yy: s\u1ed1 v\u00e9 tr\u1ebb em.<\/span><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">H\u1ec7 ph\u01b0\u01a1ng tr\u00ecnh l\u00e0:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">x+y =120\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">12x + 18y = 1200<\/span><\/p>\n<p><span style=\"font-weight: 400;\">T\u1eeb ph\u01b0\u01a1ng tr\u00ecnh \u0111\u1ea7u:\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">y=120\u2212x\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Thay v\u00e0o ph\u01b0\u01a1ng tr\u00ecnh th\u1ee9 hai:\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">12x+8(120\u2212x)=1200\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">12x+960\u22128x=1200\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">4x=240\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">x=60\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Suy ra: y=60\u00a0<\/span><\/p>\n<p><b>Answer:<\/b><span style=\"font-weight: 400;\"> 60 v\u00e9 ng\u01b0\u1eddi l\u1edbn v\u00e0 60 v\u00e9 tr\u1ebb em.\u00a0<\/span><\/p>\n<figure id=\"attachment_33798\" aria-describedby=\"caption-attachment-33798\" style=\"width: 711px\" class=\"wp-caption aligncenter\"><img decoding=\"async\" class=\"wp-image-33798 size-medium\" src=\"https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-2-23-711x400.jpg\" alt=\"\" width=\"711\" height=\"400\" srcset=\"https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-2-23-711x400.jpg 711w, https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-2-23-1400x788.jpg 1400w, https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-2-23-768x432.jpg 768w, https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-2-23-1536x864.jpg 1536w, https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-2-23-18x10.jpg 18w, https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-2-23.jpg 1920w\" sizes=\"(max-width: 711px) 100vw, 711px\" \/><figcaption id=\"caption-attachment-33798\" class=\"wp-caption-text\">B\u00e0i t\u1eadp minh h\u1ecda SAT Math<\/figcaption><\/figure>\n<h1><b>Nh\u1eefng l\u1ed7i h\u1ecdc sinh th\u01b0\u1eddng m\u1eafc<\/b><\/h1>\n<h3><b>Nh\u1ea7m ph\u01b0\u01a1ng tr\u00ecnh hai \u1ea9n v\u1edbi h\u1ec7 ph\u01b0\u01a1ng tr\u00ecnh<\/b><\/h3>\n<p><span style=\"font-weight: 400;\">Ph\u01b0\u01a1ng tr\u00ecnh:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">x+y=10\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">ch\u1ec9 c\u00f3 m\u1ed9t \u0111i\u1ec1u ki\u1ec7n n\u00ean c\u00f3 th\u1ec3 c\u00f3 v\u00f4 s\u1ed1 nghi\u1ec7m.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Trong khi h\u1ec7:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">x+y=10\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">2x+y=16<\/span><\/p>\n<p><span style=\"font-weight: 400;\">c\u00f3 th\u00eam m\u1ed9t \u0111i\u1ec1u ki\u1ec7n \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh nghi\u1ec7m.\u00a0<\/span><\/p>\n<h3><b>Kh\u00f4ng \u0111\u1ecdc k\u1ef9 \u0111\u01a1n v\u1ecb<\/b><\/h3>\n<p><span style=\"font-weight: 400;\">Trong c\u00e1c b\u00e0i to\u00e1n v\u1ec1 ti\u1ec1n, kho\u1ea3ng c\u00e1ch, th\u1eddi gian ho\u1eb7c s\u1ed1 l\u01b0\u1ee3ng, vi\u1ec7c nh\u1ea7m \u0111\u01a1n v\u1ecb c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn l\u1eadp ph\u01b0\u01a1ng tr\u00ecnh sai ngay t\u1eeb \u0111\u1ea7u.<\/span><\/p>\n<h3><b>Gi\u1ea3i \u0111\u00fang nh\u01b0ng tr\u1ea3 l\u1eddi sai \u0111\u1ea1i l\u01b0\u1ee3ng<\/b><\/h3>\n<p><span style=\"font-weight: 400;\">\u0110\u1ec1 c\u00f3 th\u1ec3 h\u1ecfi <\/span><b>t\u1ed5ng s\u1ed1<\/b><span style=\"font-weight: 400;\">, <\/span><b>s\u1ed1 l\u01b0\u1ee3ng x<\/b><span style=\"font-weight: 400;\">, <\/span><b>gi\u00e1 tr\u1ecb y<\/b><span style=\"font-weight: 400;\"> ho\u1eb7c m\u1ed9t bi\u1ec3u th\u1ee9c nh\u01b0 x+yx+y. Sau khi gi\u1ea3i \u0111\u01b0\u1ee3c h\u1ec7, h\u00e3y \u0111\u1ecdc l\u1ea1i c\u00e2u h\u1ecfi \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh ch\u00ednh x\u00e1c th\u1ee9 c\u1ea7n tr\u1ea3 l\u1eddi.<\/span><\/p>\n<h1><b>C\u00e1ch h\u1ecdc ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n \u0111\u1ec3 l\u00e0m SAT hi\u1ec7u qu\u1ea3<\/b><\/h1>\n<p><span style=\"font-weight: 400;\">H\u1ecdc sinh n\u00ean luy\u1ec7n theo th\u1ee9 t\u1ef1:<\/span><\/p>\n<p><b>Nh\u1eadn di\u1ec7n ph\u01b0\u01a1ng tr\u00ecnh \u2192 bi\u1ebfn \u0111\u1ed5i v\u1ec1 y=mx+b\u00a0 \u2192 t\u00ecm nghi\u1ec7m \u2192 gi\u1ea3i h\u1ec7 \u2192 \u0111\u1ecdc \u0111\u1ed3 th\u1ecb \u2192 l\u1eadp h\u1ec7 t\u1eeb b\u00e0i to\u00e1n th\u1ef1c t\u1ebf.<\/b><\/p>\n<p><span style=\"font-weight: 400;\">Quan tr\u1ecdng h\u01a1n, h\u00e3y t\u1eadp th\u00f3i quen x\u00e1c \u0111\u1ecbnh <\/span><b>\u00fd ngh\u0129a c\u1ee7a t\u1eebng bi\u1ebfn tr\u01b0\u1edbc khi t\u00ednh to\u00e1n<\/b><span style=\"font-weight: 400;\">. Trong nhi\u1ec1u c\u00e2u h\u1ecfi SAT, ph\u1ea7n kh\u00f3 kh\u00f4ng n\u1eb1m \u1edf ph\u00e9p c\u1ed9ng hay ph\u00e9p tr\u1eeb m\u00e0 \u1edf vi\u1ec7c chuy\u1ec3n ng\u00f4n ng\u1eef c\u1ee7a \u0111\u1ec1 b\u00e0i th\u00e0nh m\u00f4 h\u00ecnh to\u00e1n h\u1ecdc ch\u00ednh x\u00e1c.<\/span><\/p>\n<h2><b>Luy\u1ec7n SAT Math c\u00f9ng ETEST<\/b><\/h2>\n<p><span style=\"font-weight: 400;\">\u0110\u1ec3 l\u00e0m t\u1ed1t c\u00e1c c\u00e2u h\u1ecfi v\u1ec1 <\/span><b>ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n trong SAT<\/b><span style=\"font-weight: 400;\">, h\u1ecdc sinh c\u1ea7n k\u1ebft h\u1ee3p gi\u1eefa n\u1ec1n t\u1ea3ng \u0111\u1ea1i s\u1ed1, kh\u1ea3 n\u0103ng \u0111\u1ecdc \u0111\u1ec1 v\u00e0 k\u1ef9 n\u0103ng gi\u1ea3i nhanh. T\u1ea1i <\/span><a href=\"https:\/\/etest.edu.vn\/en\/\"><b>ETEST<\/b><\/a><span style=\"font-weight: 400;\">, h\u1ecdc vi\u00ean \u0111\u01b0\u1ee3c h\u1ecdc Digital SAT theo t\u1eebng nh\u00f3m ki\u1ebfn th\u1ee9c, luy\u1ec7n b\u00e0i theo d\u1ea1ng c\u00e2u h\u1ecfi v\u00e0 ph\u00e2n t\u00edch l\u1ed7i sai \u0111\u1ec3 hi\u1ec3u r\u00f5 v\u00ec sao m\u00ecnh ch\u1ecdn sai. V\u1edbi l\u1ed9 tr\u00ecnh h\u1ecdc \u0111\u01b0\u1ee3c c\u00e1 nh\u00e2n h\u00f3a theo tr\u00ecnh \u0111\u1ed9 v\u00e0 m\u1ee5c ti\u00eau \u0111i\u1ec3m s\u1ed1, h\u1ecdc sinh c\u00f3 th\u1ec3 t\u1eebng b\u01b0\u1edbc x\u00e2y d\u1ef1ng n\u1ec1n t\u1ea3ng Math v\u1eefng ch\u1eafc cho k\u1ef3 thi Digital SAT.<\/span><\/p>\n<figure id=\"attachment_33799\" aria-describedby=\"caption-attachment-33799\" style=\"width: 711px\" class=\"wp-caption aligncenter\"><img decoding=\"async\" class=\"wp-image-33799 size-medium\" src=\"https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-3-18-711x400.jpg\" alt=\"\" width=\"711\" height=\"400\" srcset=\"https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-3-18-711x400.jpg 711w, https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-3-18-1400x788.jpg 1400w, https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-3-18-768x432.jpg 768w, https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-3-18-1536x864.jpg 1536w, https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-3-18-18x10.jpg 18w, https:\/\/etest.edu.vn\/wp-content\/uploads\/2026\/09\/CHEN-LOGO-CHO-ANH-3-18.jpg 1920w\" sizes=\"(max-width: 711px) 100vw, 711px\" \/><figcaption id=\"caption-attachment-33799\" class=\"wp-caption-text\">Luy\u1ec7n SAT Math c\u00f9ng ETEST<\/figcaption><\/figure>\n<ol>\n<li><b> Ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n l\u00e0 g\u00ec?<\/b><b><br \/>\n<\/b><span style=\"font-weight: 400;\"> Ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n l\u00e0 ph\u01b0\u01a1ng tr\u00ecnh c\u00f3 d\u1ea1ng <\/span><b>ax + by = c<\/b><span style=\"font-weight: 400;\">, trong \u0111\u00f3 <\/span><i><span style=\"font-weight: 400;\">x<\/span><\/i><span style=\"font-weight: 400;\"> and <\/span><i><span style=\"font-weight: 400;\">y<\/span><\/i><span style=\"font-weight: 400;\"> l\u00e0 hai \u1ea9n, c\u00f2n <\/span><i><span style=\"font-weight: 400;\">a, b, c<\/span><\/i><span style=\"font-weight: 400;\"> l\u00e0 c\u00e1c h\u1eb1ng s\u1ed1. Ph\u01b0\u01a1ng tr\u00ecnh kh\u00f4ng ch\u1ee9a c\u00e1c bi\u1ec3u th\u1ee9c nh\u01b0 <\/span><i><span style=\"font-weight: 400;\">x\u00b2, y\u00b2<\/span><\/i><span style=\"font-weight: 400;\"> or <\/span><i><span style=\"font-weight: 400;\">xy<\/span><\/i><span style=\"font-weight: 400;\">.<\/span><\/li>\n<li><b> Ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n c\u00f3 bao nhi\u00eau nghi\u1ec7m?<\/b><b><br \/>\n<\/b><span style=\"font-weight: 400;\"> M\u1ed9t ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n th\u01b0\u1eddng c\u00f3 <\/span><b>v\u00f4 s\u1ed1 nghi\u1ec7m<\/b><span style=\"font-weight: 400;\">. M\u1ed7i c\u1eb7p gi\u00e1 tr\u1ecb <\/span><i><span style=\"font-weight: 400;\">(x, y)<\/span><\/i><span style=\"font-weight: 400;\"> th\u1ecfa m\u00e3n ph\u01b0\u01a1ng tr\u00ecnh \u0111\u01b0\u1ee3c xem l\u00e0 m\u1ed9t nghi\u1ec7m. Tr\u00ean m\u1eb7t ph\u1eb3ng t\u1ecda \u0111\u1ed9, t\u1eadp nghi\u1ec7m n\u00e0y t\u1ea1o th\u00e0nh m\u1ed9t \u0111\u01b0\u1eddng th\u1eb3ng.<\/span><\/li>\n<li><b> Ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n c\u00f3 xu\u1ea5t hi\u1ec7n trong SAT Math kh\u00f4ng?<\/b><b><br \/>\n<\/b><span style=\"font-weight: 400;\"> C\u00f3. N\u1ed9i dung n\u00e0y c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c ki\u1ec3m tra trong SAT Math d\u01b0\u1edbi nhi\u1ec1u d\u1ea1ng nh\u01b0 bi\u1ebfn \u0111\u1ed5i ph\u01b0\u01a1ng tr\u00ecnh, t\u00ecm gi\u00e1 tr\u1ecb c\u1ee7a m\u1ed9t bi\u1ebfn, gi\u1ea3i h\u1ec7 ph\u01b0\u01a1ng tr\u00ecnh, \u0111\u1ecdc \u0111\u1ed3 th\u1ecb ho\u1eb7c x\u00e2y d\u1ef1ng ph\u01b0\u01a1ng tr\u00ecnh t\u1eeb b\u00e0i to\u00e1n th\u1ef1c t\u1ebf.<\/span><\/li>\n<li><b> Ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n kh\u00e1c h\u1ec7 ph\u01b0\u01a1ng tr\u00ecnh hai \u1ea9n nh\u01b0 th\u1ebf n\u00e0o?<\/b><b><br \/>\n<\/b><span style=\"font-weight: 400;\"> M\u1ed9t ph\u01b0\u01a1ng tr\u00ecnh nh\u01b0 <\/span><b>2x + 3y = 12<\/b><span style=\"font-weight: 400;\"> c\u00f3 hai \u1ea9n v\u00e0 th\u01b0\u1eddng c\u00f3 v\u00f4 s\u1ed1 nghi\u1ec7m. Khi c\u00f3 <\/span><b>hai ph\u01b0\u01a1ng tr\u00ecnh c\u00f9ng ch\u1ee9a x v\u00e0 y<\/b><span style=\"font-weight: 400;\">, ch\u1eb3ng h\u1ea1n:<\/span><\/li>\n<\/ol>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">2x + 3y = 12<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">x \u2212 y = 1<\/span><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">ta c\u00f3 m\u1ed9t <\/span><b>h\u1ec7 ph\u01b0\u01a1ng tr\u00ecnh hai \u1ea9n<\/b><span style=\"font-weight: 400;\">. Khi \u0111\u00f3, nhi\u1ec7m v\u1ee5 th\u01b0\u1eddng l\u00e0 t\u00ecm c\u1eb7p <\/span><i><span style=\"font-weight: 400;\">(x, y)<\/span><\/i><span style=\"font-weight: 400;\"> th\u1ecfa m\u00e3n \u0111\u1ed3ng th\u1eddi c\u1ea3 hai ph\u01b0\u01a1ng tr\u00ecnh.<\/span><\/p>\n<ol start=\"5\">\n<li><b> C\u00f3 nh\u1eefng c\u00e1ch n\u00e0o \u0111\u1ec3 gi\u1ea3i h\u1ec7 ph\u01b0\u01a1ng tr\u00ecnh hai \u1ea9n trong SAT?<\/b><b><br \/>\n<\/b><span style=\"font-weight: 400;\"> C\u00e1c ph\u01b0\u01a1ng ph\u00e1p th\u01b0\u1eddng g\u1eb7p g\u1ed3m <\/span><b>th\u1ebf, c\u1ed9ng \u0111\u1ea1i s\u1ed1 v\u00e0 \u0111\u1ed3 th\u1ecb<\/b><span style=\"font-weight: 400;\">. Trong SAT, h\u1ecdc sinh n\u00ean ch\u1ecdn ph\u01b0\u01a1ng ph\u00e1p ph\u00f9 h\u1ee3p v\u1edbi c\u1ea5u tr\u00fac c\u1ee7a t\u1eebng c\u00e2u h\u1ecfi \u0111\u1ec3 gi\u1ea3m s\u1ed1 b\u01b0\u1edbc t\u00ednh to\u00e1n v\u00e0 h\u1ea1n ch\u1ebf sai s\u00f3t.<\/span><\/li>\n<li><b> L\u00e0m th\u1ebf n\u00e0o \u0111\u1ec3 nh\u1eadn bi\u1ebft ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n trong \u0111\u1ec1 SAT?<\/b><b><br \/>\n<\/b><span style=\"font-weight: 400;\"> H\u00e3y ki\u1ec3m tra xem ph\u01b0\u01a1ng tr\u00ecnh c\u00f3 hai bi\u1ebfn, th\u01b0\u1eddng l\u00e0 <\/span><i><span style=\"font-weight: 400;\">x<\/span><\/i><span style=\"font-weight: 400;\"> and <\/span><i><span style=\"font-weight: 400;\">y<\/span><\/i><span style=\"font-weight: 400;\">, v\u00e0 m\u1ed7i bi\u1ebfn ch\u1ec9 c\u00f3 <\/span><b>b\u1eadc 1<\/b><span style=\"font-weight: 400;\"> hay kh\u00f4ng. C\u00e1c d\u1ea1ng nh\u01b0 <\/span><b>3x + 2y = 10<\/b><span style=\"font-weight: 400;\"> or <\/span><b>y = 4x \u2212 7<\/b><span style=\"font-weight: 400;\"> l\u00e0 ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n.<\/span><\/li>\n<li><b> B\u00e0i to\u00e1n th\u1ef1c t\u1ebf trong SAT c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng h\u1ec7 ph\u01b0\u01a1ng tr\u00ecnh hai \u1ea9n nh\u01b0 th\u1ebf n\u00e0o?<\/b><b><br \/>\n<\/b><span style=\"font-weight: 400;\"> SAT c\u00f3 th\u1ec3 \u0111\u01b0a ra c\u00e1c t\u00ecnh hu\u1ed1ng nh\u01b0 <\/span><b>gi\u00e1 v\u00e9, s\u1ed1 l\u01b0\u1ee3ng s\u1ea3n ph\u1ea9m, qu\u00e3ng \u0111\u01b0\u1eddng, chi ph\u00ed ho\u1eb7c s\u1ed1 l\u01b0\u1ee3ng h\u1ecdc sinh<\/b><span style=\"font-weight: 400;\">. H\u1ecdc sinh c\u1ea7n x\u00e1c \u0111\u1ecbnh hai \u0111\u1ea1i l\u01b0\u1ee3ng ch\u01b0a bi\u1ebft, \u0111\u1eb7t \u1ea9n v\u00e0 x\u00e2y d\u1ef1ng hai ph\u01b0\u01a1ng tr\u00ecnh t\u1eeb th\u00f4ng tin \u0111\u1ec1 b\u00e0i tr\u01b0\u1edbc khi gi\u1ea3i.<\/span><\/li>\n<li><b> H\u1ecdc ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n c\u1ea7n ch\u00fa \u00fd \u0111i\u1ec1u g\u00ec khi l\u00e0m SAT?<\/b><b><br \/>\n<\/b><span style=\"font-weight: 400;\"> Ngo\u00e0i k\u1ef9 n\u0103ng gi\u1ea3i ph\u01b0\u01a1ng tr\u00ecnh, h\u1ecdc sinh c\u1ea7n ch\u00fa \u00fd <\/span><b>\u0111\u01a1n v\u1ecb, d\u1ea5u \u00e2m, \u0111i\u1ec1u ki\u1ec7n c\u1ee7a b\u00e0i to\u00e1n v\u00e0 ch\u00ednh x\u00e1c \u0111\u1ea1i l\u01b0\u1ee3ng m\u00e0 c\u00e2u h\u1ecfi y\u00eau c\u1ea7u<\/b><span style=\"font-weight: 400;\">. M\u1ed9t l\u1ed7i ph\u1ed5 bi\u1ebfn l\u00e0 gi\u1ea3i \u0111\u00fang h\u1ec7 ph\u01b0\u01a1ng tr\u00ecnh nh\u01b0ng ch\u1ecdn nh\u1ea7m gi\u00e1 tr\u1ecb c\u1ea7n tr\u1ea3 l\u1eddi.<\/span><\/li>\n<li><b> M\u00e1y t\u00ednh c\u00f3 h\u1ed7 tr\u1ee3 gi\u1ea3i h\u1ec7 ph\u01b0\u01a1ng tr\u00ecnh trong Digital SAT kh\u00f4ng?<\/b><\/li>\n<\/ol>\n<p><span style=\"font-weight: 400;\">Trong Digital SAT Math, h\u1ecdc sinh c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng m\u00e1y t\u00ednh \u0111\u01b0\u1ee3c ph\u00e9p trong to\u00e0n b\u1ed9 ph\u1ea7n Math. Tuy nhi\u00ean, v\u1edbi nh\u1eefng h\u1ec7 ph\u01b0\u01a1ng tr\u00ecnh \u0111\u01a1n gi\u1ea3n, hi\u1ec3u c\u00e1ch bi\u1ebfn \u0111\u1ed5i \u0111\u1ea1i s\u1ed1 v\u1eabn quan tr\u1ecdng v\u00ec gi\u00fap h\u1ecdc sinh ki\u1ec3m so\u00e1t b\u00e0i l\u00e0m v\u00e0 x\u1eed l\u00fd nhanh nh\u1eefng c\u00e2u h\u1ecfi kh\u00f4ng c\u1ea7n nhi\u1ec1u ph\u00e9p t\u00ednh.\u00a0<\/span><\/p>\n\n\n<div class=\"kk-star-ratings kksr-auto kksr-align-left kksr-valign-bottom\"\n    data-payload='{&quot;align&quot;:&quot;left&quot;,&quot;id&quot;:&quot;33795&quot;,&quot;slug&quot;:&quot;default&quot;,&quot;valign&quot;:&quot;bottom&quot;,&quot;ignore&quot;:&quot;&quot;,&quot;reference&quot;:&quot;auto&quot;,&quot;class&quot;:&quot;&quot;,&quot;count&quot;:&quot;633&quot;,&quot;legendonly&quot;:&quot;&quot;,&quot;readonly&quot;:&quot;&quot;,&quot;score&quot;:&quot;5&quot;,&quot;starsonly&quot;:&quot;&quot;,&quot;best&quot;:&quot;5&quot;,&quot;gap&quot;:&quot;5&quot;,&quot;greet&quot;:&quot;\u0110\u00e1nh gi\u00e1 b\u00e0i vi\u1ebft&quot;,&quot;legend&quot;:&quot;5\\\/5 - (633 votes)&quot;,&quot;size&quot;:&quot;24&quot;,&quot;title&quot;:&quot;Ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n trong SAT: C\u00e1ch gi\u1ea3i, nh\u1eadn di\u1ec7n v\u00e0 b\u00e0i t\u1eadp minh h\u1ecda&quot;,&quot;width&quot;:&quot;142.5&quot;,&quot;_legend&quot;:&quot;{score}\\\/{best} - ({count} {votes})&quot;,&quot;font_factor&quot;:&quot;1.25&quot;}'>\n            \n<div class=\"kksr-stars\">\n    \n<div class=\"kksr-stars-inactive\">\n            <div class=\"kksr-star\" data-star=\"1\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" data-star=\"2\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" data-star=\"3\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" data-star=\"4\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" data-star=\"5\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n    <\/div>\n    \n<div class=\"kksr-stars-active\" style=\"width: 142.5px;\">\n            <div class=\"kksr-star\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n            <div class=\"kksr-star\" style=\"padding-right: 5px\">\n            \n\n<div class=\"kksr-icon\" style=\"width: 24px; height: 24px;\"><\/div>\n        <\/div>\n    <\/div>\n<\/div>\n                \n\n<div class=\"kksr-legend\" style=\"font-size: 19.2px;\">\n            5\/5 - (633 votes)    <\/div>\n    <\/div>","protected":false},"excerpt":{"rendered":"<p>Ph\u01b0\u01a1ng tr\u00ecnh b\u1eadc nh\u1ea5t hai \u1ea9n l\u00e0 m\u1ed9t ch\u1ee7 \u0111\u1ec1 quan tr\u1ecdng trong SAT Math, \u0111\u1eb7c bi\u1ec7t khi \u0111\u1ec1 b\u00e0i y\u00eau c\u1ea7u h\u1ecdc sinh l\u1eadp ph\u01b0\u01a1ng tr\u00ecnh t\u1eeb d\u1eef ki\u1ec7n th\u1ef1c t\u1ebf, x\u00e1c \u0111\u1ecbnh m\u1ed9t c\u1eb7p nghi\u1ec7m ho\u1eb7c k\u1ebft h\u1ee3p hai ph\u01b0\u01a1ng tr\u00ecnh \u0111\u1ec3 t\u00ecm gi\u00e1 tr\u1ecb c\u1ee7a c\u00e1c bi\u1ebfn. N\u1ebfu n\u1eafm \u0111\u01b0\u1ee3c c\u00e1ch nh\u1eadn [&#8230;]","protected":false},"author":24,"featured_media":33796,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":""},"categories":[1,285],"tags":[],"class_list":["post-33795","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-tin-tuc","category-sat"],"acf":[],"_links":{"self":[{"href":"https:\/\/etest.edu.vn\/en\/wp-json\/wp\/v2\/posts\/33795","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/etest.edu.vn\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/etest.edu.vn\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/etest.edu.vn\/en\/wp-json\/wp\/v2\/users\/24"}],"replies":[{"embeddable":true,"href":"https:\/\/etest.edu.vn\/en\/wp-json\/wp\/v2\/comments?post=33795"}],"version-history":[{"count":1,"href":"https:\/\/etest.edu.vn\/en\/wp-json\/wp\/v2\/posts\/33795\/revisions"}],"predecessor-version":[{"id":33800,"href":"https:\/\/etest.edu.vn\/en\/wp-json\/wp\/v2\/posts\/33795\/revisions\/33800"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/etest.edu.vn\/en\/wp-json\/wp\/v2\/media\/33796"}],"wp:attachment":[{"href":"https:\/\/etest.edu.vn\/en\/wp-json\/wp\/v2\/media?parent=33795"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/etest.edu.vn\/en\/wp-json\/wp\/v2\/categories?post=33795"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/etest.edu.vn\/en\/wp-json\/wp\/v2\/tags?post=33795"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}