{"common":{"save":0,"post_id":"7755","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"7296","post_id":"7755","mon_id":"1159278","chapter_id":"1159281","question":"<p>H\u1ec7 ph\u01b0\u01a1ng tr&igrave;nh&nbsp;<span class=\"math-tex\">$\\begin{cases}\\dfrac{4}{2x-3y}+\\dfrac{5}{3x+y}=-2\\\\\\dfrac{5}{2x-3y}-\\dfrac{3}{3x+y}=-21\\end{cases}$<\/span>&nbsp;&nbsp;c&oacute; nghi\u1ec7m l&agrave;:<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$\\bigg(-\\dfrac{7}{66};\\dfrac{2}{11}\\bigg)$<\/span>","<strong>B.<\/strong> <span class=\"math-tex\">$\\bigg(\\dfrac{7}{66};-\\dfrac{2}{11}\\bigg)$<\/span>","<strong>C.<\/strong> <span class=\"math-tex\">$\\bigg(-\\dfrac{7}{66};-\\dfrac{2}{11}\\bigg)$<\/span>","<strong>D.<\/strong> <span class=\"math-tex\">$\\bigg(\\dfrac{7}{66};\\dfrac{2}{11}\\bigg)$<\/span>"],"correct":"4","level":"3","hint":"","answer":"<p>Ch\u1ecdn&nbsp;<span style=\"color:#16a085;\"><strong>D.<\/strong>&nbsp;<span class=\"math-tex\">$\\bigg(\\dfrac{7}{66};\\dfrac{2}{11}\\bigg)$<\/span>.<\/span><\/p><p>Nh&acirc;n&nbsp;2 v\u1ebf ph\u01b0\u01a1ng tr&igrave;nh th\u1ee9 nh\u1ea5t v\u1edbi 5, ph\u01b0\u01a1ng tr&igrave;nh th\u1ee9 hai v\u1edbi 4 ta \u0111\u01b0\u1ee3c&nbsp;<span class=\"math-tex\">$\\begin{cases}\\dfrac{20}{2x-3y}+\\dfrac{25}{3x+y}=-10\\\\\\dfrac{20}{2x-3y}-\\dfrac{12}{3x+y}=-84\\end{cases}$<\/span>.<\/p><p>Tr\u1eeb t\u1eebng v\u1ebf c\u1ee7a hai ph\u01b0\u01a1ng tr&igrave;nh m\u1edbi ta \u0111\u01b0\u1ee3c&nbsp;<span class=\"math-tex\">$\\dfrac{37}{3x+y}=74$<\/span>&nbsp;hay&nbsp;<span class=\"math-tex\">$3x+y=\\dfrac{1}{2}$<\/span>&nbsp;(1).<\/p><p>Thay&nbsp;<span class=\"math-tex\">$3x+y=\\dfrac{1}{2}$<\/span>&nbsp;v&agrave;o ph\u01b0\u01a1ng tr&igrave;nh th\u1ee9 nh\u1ea5t c\u1ee7a h\u1ec7 ban \u0111\u1ea7u ta \u0111\u01b0\u1ee3c&nbsp;<span class=\"math-tex\">$\\dfrac{4}{2x-3y}+10=-2$<\/span>&nbsp;hay&nbsp;<span class=\"math-tex\">$2x-3y=\\dfrac{-1}{3}$<\/span>&nbsp;(2).<\/p><p>T\u1eeb (1) v&agrave; (2) ta c&oacute; h\u1ec7&nbsp;<span class=\"math-tex\">$\\begin{cases}2x-3y=-\\dfrac{1}{3}\\\\3x+y=\\dfrac{1}{2}\\end{cases}$<\/span>&nbsp; .<\/p><p>Nh&acirc;n 2 v\u1ebf c\u1ee7a ph\u01b0\u01a1ng tr&igrave;nh th\u1ee9 hai v\u1edbi 3 ta \u0111\u01b0\u1ee3c&nbsp;<span class=\"math-tex\">$\\begin{cases}2x-3y=-\\dfrac{1}{3}\\\\9x+3y=\\dfrac{3}{2}\\end{cases}$<\/span>.<\/p><p>C&ocirc;ng t\u1eebng v\u1ebf&nbsp;c\u1ee7a hai ph\u01b0\u01a1ng tr&igrave;nh ta \u0111\u01b0\u1ee3c&nbsp;<span class=\"math-tex\">$11x=\u200b\\dfrac{7}{6}\u200b$<\/span>, suy ra&nbsp;<span class=\"math-tex\">$x=\\dfrac{7}{66}$<\/span>.<\/p><p>Thay v&agrave;o ph\u01b0\u01a1ng tr&igrave;nh (1) ta \u0111\u01b0\u1ee3c&nbsp;<span class=\"math-tex\">$\\dfrac{7}{22}+y=\\dfrac{1}{2}$<\/span>, suy ra&nbsp;<span class=\"math-tex\">$y=\\dfrac{2}{11}$<\/span>.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2024-10-05 00:56:22","option_type":"math","len":0},{"id":"7297","post_id":"7755","mon_id":"1159278","chapter_id":"1159281","question":"<p>T&igrave;m c&aacute;c gi&aacute; tr\u1ecb c\u1ee7a tham s\u1ed1 m \u0111\u1ec3 c\u1eb7p s\u1ed1 (2 ; &ndash;1) l&agrave; nghi\u1ec7m c\u1ee7a ph\u01b0\u01a1ng tr&igrave;nh<br \/>x &ndash; 5y = 2m &ndash; 3.<\/p>","options":["<strong>A.<\/strong> 5","<strong>B.<\/strong> 6","<strong>C.<\/strong> 10","<strong>D.<\/strong> 3"],"correct":"1","level":"3","hint":"","answer":"<p>Ch\u1ecdn&nbsp;<span style=\"color:#16a085;\"><strong>A.<\/strong>&nbsp;5.<\/span><\/p><p>\u0110\u1ec3 c\u1eb7p s\u1ed1 (2 ; &ndash;1) l&agrave; nghi\u1ec7m c\u1ee7a ph\u01b0\u01a1ng tr&igrave;nh x &ndash; 5y = 2m &ndash; 3 th&igrave;: 2 &ndash; 5. (&ndash;1) = 2m &ndash; 3 hay<br \/>m = 5.<br \/>V\u1eady v\u1edbi m = 5&nbsp;th&igrave; (2; &ndash;1) l&agrave; nghi\u1ec7m c\u1ee7a ph\u01b0\u01a1ng tr&igrave;nh \u0111&atilde; cho.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2024-10-05 01:07:03","option_type":"txt","len":0},{"id":"7298","post_id":"7755","mon_id":"1159278","chapter_id":"1159281","question":"<p>T&igrave;m c&aacute;c gi&aacute; tr\u1ecb c\u1ee7a tham s\u1ed1 m \u0111\u1ec3 c\u1eb7p s\u1ed1 (&ndash;3; &ndash;2) l&agrave; nghi\u1ec7m c\u1ee7a ph\u01b0\u01a1ng tr&igrave;nh (2m &ndash; 3)x + (3m &ndash; 1)y&nbsp;= m + 2.<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$\\dfrac{9}{11}$<\/span>","<strong>B.<\/strong> <span class=\"math-tex\">$\\dfrac{13}{9}$<\/span>","<strong>C.<\/strong> <span class=\"math-tex\">$\\dfrac{9}{13}$<\/span>","<strong>D.<\/strong> <span class=\"math-tex\">$\\dfrac{11}{9}$<\/span>"],"correct":"3","level":"3","hint":"","answer":"<p>Ch\u1ecdn&nbsp;<span style=\"color:#16a085;\"><strong>C.<\/strong>&nbsp;<span class=\"math-tex\">$\\dfrac{9}{13}$<\/span>.<\/span><\/p><p>C\u1eb7p s\u1ed1 <span class=\"math-tex\">$(-3;-2)$<\/span> l&agrave; nghi\u1ec7m c\u1ee7a ph\u01b0\u01a1ng tr&igrave;nh (2m &ndash; 3)x + (3m &ndash; 1)y = m + 2 khi&nbsp;<span class=\"math-tex\">$(2m-3).(-3)+(3m-1).(-2)=m+2$<\/span>&nbsp;hay&nbsp;<span class=\"math-tex\">$13m=9$<\/span>, suy ra&nbsp;<span class=\"math-tex\">$m=\\dfrac{9}{13}$<\/span>.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2024-10-05 01:13:01","option_type":"math","len":0}]}