{"common":{"save":0,"post_id":"7946","level":2,"total":10,"point":10,"point_extra":0},"segment":[{"id":"8625","post_id":"7946","mon_id":"1159278","chapter_id":"1159330","question":"<p>Ph\u01b0\u01a1ng trình <span class=\"math-tex\">$5x^2-7x=0$<\/span> có nghi\u1ec7m là:<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$x=0;x=-\\dfrac{7}{5}$<\/span>","<strong>B.<\/strong> <span class=\"math-tex\">$x=0;x=\\dfrac{7}{5}$<\/span>","<strong>C.<\/strong> <span class=\"math-tex\">$x=0;x=-\\dfrac{5}{7}$<\/span>","<strong>D.<\/strong> <span class=\"math-tex\">$x=0;x=\\dfrac{5}{7}$<\/span>"],"correct":"2","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>B.<\/strong> <span class=\"math-tex\">$x=0;x=\\dfrac{7}{5}$<\/span><\/span><\/p><p><span class=\"math-tex\">$5x^2-7x=0$<\/span><\/p><p><span class=\"math-tex\">$x(5x-7)=0$<\/span><\/p><p>x = 0 ho\u1eb7c x = <span class=\"math-tex\">$\\dfrac{7}{5}$<\/span><\/p><p>V\u1eady ph\u01b0\u01a1ng trình có nghi\u1ec7m <span class=\"math-tex\">$x=0;x=\\dfrac{7}{5}$<\/span>.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2024-11-17 09:23:48","option_type":"math","len":0},{"id":"8627","post_id":"7946","mon_id":"1159278","chapter_id":"1159330","question":"<p>Ph\u01b0\u01a1ng trình <span class=\"math-tex\">$x^2-6x+5=0$<\/span> có m\u1ea5y nghi\u1ec7m:<\/p>","options":["<strong>A.<\/strong> 0","<strong>B.<\/strong> 1","<strong>C.<\/strong> 2","<strong>D.<\/strong> 3"],"correct":"3","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>C.<\/strong> 2<\/span><\/p><p>Ta có: Δ = (–6)² – 4 . 1 . 5 = 16 > 0.<\/p><p>V\u1eady ph\u01b0\u01a1ng trình \u0111ã cho có hai nghi\u1ec7m phân bi\u1ec7t.<\/p>","type":"choose","extra_type":"flower","time":"0","user_id":"127","test":"0","date":"2024-11-17 09:25:56","option_type":"txt","len":0},{"id":"8628","post_id":"7946","mon_id":"1159278","chapter_id":"1159330","question":"<p>Ph\u01b0\u01a1ng trình <span class=\"math-tex\">$3x^2+12x+1=0$<\/span> có nghi\u1ec7m là:<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$x=\\dfrac{-6\\pm\\sqrt{33}}{3}$<\/span>","<strong>B.<\/strong> <span class=\"math-tex\">$x=\\dfrac{6\\pm\\sqrt{33}}{3}$<\/span>","<strong>C.<\/strong> <span class=\"math-tex\">$x=\\dfrac{-6\\pm\\sqrt{33}}{6}$<\/span>","<strong>D.<\/strong> <span class=\"math-tex\">$x=\\dfrac{6\\pm\\sqrt{33}}{6}$<\/span>"],"correct":"1","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>A.<\/strong> <span class=\"math-tex\">$x=\\dfrac{-6\\pm\\sqrt{33}}{3}$<\/span><\/span><\/p><p>Ta có: Δ' = 6² – 3 . 1 = 33 > 0.<\/p><p>Suy ra ph\u01b0\u01a1ng trình \u0111ã cho có hai nghi\u1ec7m phân bi\u1ec7t là <span class=\"math-tex\">$x=\\dfrac{-6\\pm\\sqrt{33}}{3}$<\/span>.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2024-11-17 09:29:10","option_type":"math","len":0}]}
