{"common":{"save":0,"post_id":"7947","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"8645","post_id":"7947","mon_id":"1159278","chapter_id":"1159330","question":"<p>Ph\u01b0\u01a1ng tr&igrave;nh&nbsp;<span class=\"math-tex\">$(m^2+2)x^2-5=0$<\/span>&nbsp;v\u1edbi&nbsp;<span class=\"math-tex\">$m\\in \\mathbb R$<\/span>&nbsp;c&oacute; nghi\u1ec7m:<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$x = \\sqrt{\\dfrac{-5}{m^2+2}}$<\/span>; <span class=\"math-tex\">$x =-\\sqrt{\\dfrac{-5}{m^2+2}}$<\/span>","<strong>B.<\/strong> <span class=\"math-tex\">$x = \\sqrt{\\dfrac{5}{m^2+2}}$<\/span>; <span class=\"math-tex\">$x =\\sqrt{\\dfrac{-5}{m^2+2}}$<\/span>","<strong>C.<\/strong> <span class=\"math-tex\">$x = \\sqrt{\\dfrac{5}{m^2+2}}$<\/span>; <span class=\"math-tex\">$x =-\\sqrt{\\dfrac{5}{m^2+2}}$<\/span>","<strong>D.<\/strong> <span class=\"math-tex\">$x = \\sqrt{\\dfrac{m^2+2}{5}}$<\/span>; <span class=\"math-tex\">$x = -\\sqrt{\\dfrac{m^2+2}{5}}$<\/span>"],"correct":"3","level":"3","hint":"","answer":"<p>Ch\u1ecdn&nbsp;<span style=\"color:#16a085;\"><strong>C.<\/strong>&nbsp;<span class=\"math-tex\">$x = \\sqrt{\\dfrac{5}{m^2+2}}$<\/span>;&nbsp;<span class=\"math-tex\">$x =-\\sqrt{\\dfrac{5}{m^2+2}}$<\/span><\/span><\/p><p><span class=\"math-tex\">$(m^2+2)x^2-5=0$<\/span><\/p><p>suy ra&nbsp;<span class=\"math-tex\">$x^2=\\dfrac{5}{m^2+2}$<\/span><\/p><p>suy ra&nbsp;<span class=\"math-tex\">$x = \\sqrt{\\dfrac{5}{m^2+2}}$<\/span>&nbsp;ho\u1eb7c&nbsp;<span class=\"math-tex\">$x =-\\sqrt{\\dfrac{5}{m^2+2}}$<\/span><\/p><p>(v&igrave;&nbsp;<span class=\"math-tex\">$m^2\\ge 0$<\/span>&nbsp;v\u1edbi m\u1ecdi m n&ecirc;n&nbsp;<span class=\"math-tex\">$m^2+2> 0$<\/span>&nbsp;v\u1edbi m\u1ecdi m).<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2024-11-17 10:13:49","option_type":"math","len":0},{"id":"8647","post_id":"7947","mon_id":"1159278","chapter_id":"1159330","question":"<p>V\u1edbi gi&aacute; tr\u1ecb n&agrave;o c\u1ee7a tham s\u1ed1 m th&igrave; ph\u01b0\u01a1ng tr&igrave;nh&nbsp;<span class=\"math-tex\">$4x^2+m^2x+4m=0$<\/span>&nbsp;c&oacute; nghi\u1ec7m x = 1?<\/p>","options":["<strong>A.<\/strong> m = &ndash;4","<strong>B.<\/strong> m = 4","<strong>C.<\/strong> m = 2","<strong>D.<\/strong> m = &ndash;2"],"correct":"4","level":"3","hint":"","answer":"<p>Ch\u1ecdn&nbsp;<span style=\"color:#1abc9c;\"><\/span><span style=\"color:#16a085;\"><strong>D.<\/strong>&nbsp;m = &ndash;2<\/span><\/p><p>\u0110\u1ec3&nbsp;ph\u01b0\u01a1ng tr&igrave;nh&nbsp;<span class=\"math-tex\">$4x^2+m^2x+4m=0$<\/span>&nbsp;c&oacute; nghi\u1ec7m x = 1 th&igrave;<\/p><p><span class=\"math-tex\">$4.1^2+m^2.1+4m=0$<\/span>&nbsp;hay&nbsp;<span class=\"math-tex\">$m^2+4m+4=0$<\/span>&nbsp;hay&nbsp;<span class=\"math-tex\">$(m+2)^2=0$<\/span>&nbsp;suy ra m =&nbsp;&ndash;2.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2024-11-17 10:17:05","option_type":"txt","len":1},{"id":"8650","post_id":"7947","mon_id":"1159278","chapter_id":"1159330","question":"<p>C&oacute; bao nhi&ecirc;u gi&aacute; tr\u1ecb c\u1ee7a m \u0111\u1ec3 ph\u01b0\u01a1ng tr&igrave;nh&nbsp;<span class=\"math-tex\">$x^2-(2m+1)x+m^2-2m+3=0$<\/span> c&oacute; nghi\u1ec7m <span class=\"math-tex\">$x=2$<\/span>?<\/p>","options":["<strong>A.<\/strong> 0","<strong>B.<\/strong> 1","<strong>C.<\/strong> 2","<strong>D.<\/strong> 3"],"correct":"3","level":"3","hint":"","answer":"<p>Ch\u1ecdn&nbsp;<span style=\"color:#16a085;\"><strong>C.<\/strong>&nbsp;2<\/span><\/p><p>\u0110\u1ec3 ph\u01b0\u01a1ng tr&igrave;nh&nbsp;<span class=\"math-tex\">$x^2-(2m+1)x+m^2-2m+3=0$<\/span> c&oacute; nghi\u1ec7m <span class=\"math-tex\">$x=2$<\/span>&nbsp;th&igrave;<\/p><p><span class=\"math-tex\">$2^2-(2m+1).2+m^2-2m+3=0$<\/span>&nbsp;hay&nbsp;<span class=\"math-tex\">$m^2-6m+5=0$<\/span><\/p><p>suy ra&nbsp;<span class=\"math-tex\">$(m-1)(m-5)=0$<\/span>&nbsp;suy ra m = 1 ho\u1eb7c m = 5.<\/p><p>V\u1eady c&oacute; 2 gi&aacute; tr\u1ecb c\u1ee7a m \u0111\u1ec3 ph\u01b0\u01a1ng tr&igrave;nh c&oacute; nghi\u1ec7m x = 2.<\/p>","type":"choose","extra_type":"star","time":"0","user_id":"127","test":"0","date":"2024-11-17 10:26:36","option_type":"txt","len":0}]}