{"common":{"save":0,"post_id":"6549","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"5865","post_id":"6549","mon_id":"1158921","chapter_id":"1158928","question":"<p>Tìm x, bi\u1ebft x³ + 3x² + 3x + 1 = 27 .<\/p>","options":["<strong>A.<\/strong> x = 2","<strong>B.<\/strong> x = 1","<strong>C.<\/strong> x = 0","<strong>D.<\/strong> x = 3"],"correct":"1","level":"3","hint":"","answer":"<p>x³ + 3x² + 3x + 1 = 27<\/p><p>x³ + 3.x².1 + 3.x.1² + 1³ = 27<\/p><p> (x + 1)³ = 27<\/p><p> (x + 1)³ = 3³<\/p><p> x + 1 = 3<\/p><p> x = 3 – 1<\/p><p> x = 2<\/p><p>\u0110áp án \u0111úng là <span style=\"color:#16a085;\"> <strong>A.<\/strong> x = 2.<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"0","date":"2023-07-04 14:58:52","option_type":"txt","len":0},{"id":"5868","post_id":"6549","mon_id":"1158921","chapter_id":"1158928","question":"<p>Tìm x, bi\u1ebft x³ – 3x² + 3x – 1 = 8 .<\/p>","options":["<strong>A.<\/strong> x = 0","<strong>B.<\/strong> x = 1","<strong>C.<\/strong> x = 2","<strong>D.<\/strong> x = 3"],"correct":"4","level":"3","hint":"","answer":"<p>x³ – 3x² + 3x – 1 = 8<\/p><p>x³ – 3.x².1 + 3.x.1² – 1³ = 8<\/p><p> (x – 1)³ = 8<\/p><p> (x – 1)³ = 2³<\/p><p> x – 1 = 2<\/p><p> x = 2 + 1<\/p><p> x = 3<\/p><p>\u0110áp án \u0111úng là <span style=\"color:#16a085;\"> <strong>D.<\/strong> x = 3.<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"0","date":"2023-07-04 15:02:40","option_type":"txt","len":0},{"id":"5869","post_id":"6549","mon_id":"1158921","chapter_id":"1158928","question":"<p>Tìm x, bi\u1ebft 1 – 3x + 3x² – x³ = 8 .<\/p>","options":["<strong>A.<\/strong> x = 1","<strong>B.<\/strong> x = –1","<strong>C.<\/strong> x = 2","<strong>D.<\/strong> x = –2"],"correct":"2","level":"3","hint":"","answer":"<p>1 – 3x + 3x² – x³ = 8 <\/p><p>1³ – 3.1².x + 3.1.x² – x³ = 8<\/p><p>(1 – x)³ = 8<\/p><p>(1 – x)³ = 2³<\/p><p>1 – x = 2<\/p><p> – x = 2 – 1<\/p><p> – x = 1<\/p><p> x = –1<\/p><p>\u0110áp án \u0111úng là <span style=\"color:#16a085;\"><strong>B.<\/strong> x = –1.<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"0","date":"2023-07-04 15:06:37","option_type":"txt","len":1}]}