{"common":{"save":0,"post_id":"7101","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"5385","post_id":"7101","mon_id":"1158924","chapter_id":"1159168","question":"<p>\u0110\u1eb7t <span class=\"math-tex\">$a=\\ln2$<\/span>, <span class=\"math-tex\">$b=\\ln3$<\/span>. Hãy bi\u1ec3u di\u1ec5n <span class=\"math-tex\">$\\ln36$<\/span> theo a và b.<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$2a+2b$<\/span>","<strong>B.<\/strong> <span class=\"math-tex\">$a+b$<\/span>","<strong>C.<\/strong> <span class=\"math-tex\">$a-b$<\/span>","<strong>D.<\/strong> <span class=\"math-tex\">$2a-2b$<\/span>"],"correct":"1","level":"3","hint":"","answer":"<p><span class=\"math-tex\">$\\ln36=\\ln(2^2.3^2)$<\/span> <span class=\"math-tex\">$=2\\ln2+2\\ln3$<\/span> <span class=\"math-tex\">$=2a+2b$<\/span><\/p><p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>A.<\/strong> <span class=\"math-tex\">$2a+2b$<\/span>.<\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2024-03-31 03:53:35","option_type":"math","len":0},{"id":"5388","post_id":"7101","mon_id":"1158924","chapter_id":"1159168","question":"<p>Cho x, y, z là các s\u1ed1 th\u1ef1c d\u01b0\u01a1ng tùy ý khác 1 và xyz <span class=\"math-tex\">$\\ne$<\/span> 1. \u0110\u1eb7t <span class=\"math-tex\">$a=\\log_xy$<\/span>, <span class=\"math-tex\">$b=\\log_zy$<\/span>. Tính <span class=\"math-tex\">$\\log_{xyz}(y^5z^3)$<\/span>.<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$\\dfrac{5ab+3a}{a+b+1}$<\/span>","<strong>B.<\/strong> <span class=\"math-tex\">$\\dfrac{5ab+3b}{ab+a+b}$<\/span>","<strong>C.<\/strong> <span class=\"math-tex\">$\\dfrac{5ab+3a}{ab+a+b}$<\/span>","<strong>D.<\/strong> <span class=\"math-tex\">$\\dfrac{5ab+3b}{a+b+1}$<\/span>"],"correct":"3","level":"3","hint":"","answer":"<p><span class=\"math-tex\">$\\log_{xyz}(y^5z^3)$<\/span><span class=\"math-tex\">$=5\\log_{xyz}y+3\\log_{xyz}z$<\/span><\/p><p><span class=\"math-tex\">$=\\dfrac{5}{\\log_y(xyz)}+\\dfrac{3}{\\log_z(xyz)}$<\/span><\/p><p><span class=\"math-tex\">$=\\dfrac{5}{\\log_yx+\\log_yz+1}+\\dfrac{3}{\\log_zx+\\log_zy+1}$<\/span><\/p><p><span class=\"math-tex\">$=\\dfrac{5}{\\log_yx+\\log_yz+1}+\\dfrac{3}{\\log_zy.\\log_yx+\\log_zy+1}$<\/span><\/p><p><span class=\"math-tex\">$=\\dfrac{5}{\\dfrac{1}{a}+\\dfrac{1}{b}+1}+\\dfrac{3}{\\dfrac{b}{a}+b+1}$<\/span><\/p><p><span class=\"math-tex\">$=\\dfrac{5ab}{ab+a+b}+\\dfrac{3a}{ab+a+b}$<\/span><\/p><p><span class=\"math-tex\">$=\\dfrac{5ab+3a}{ab+a+b}$<\/span><\/p><p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>C.<\/strong> <span class=\"math-tex\">$\\dfrac{5ab+3a}{ab+a+b}$<\/span>.<\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2024-03-31 04:06:28","option_type":"math","len":0},{"id":"5390","post_id":"7101","mon_id":"1158924","chapter_id":"1159168","question":"<p>Cho a, y, z là các s\u1ed1 th\u1ef1c l\u1edbn h\u01a1n 1 và g\u1ecdi w là s\u1ed1 th\u1ef1c d\u01b0\u01a1ng sao cho <span class=\"math-tex\">$\\log_xw=12$<\/span>, <span class=\"math-tex\">$\\log_yw=20$<\/span> và <span class=\"math-tex\">$\\log_{xyz}w=6$<\/span>. Tính <span class=\"math-tex\">$\\log_zw$<\/span>.<\/p>","options":["<strong>A.<\/strong> 34","<strong>B.<\/strong> –30","<strong>C.<\/strong> 30","<strong>D.<\/strong> –34"],"correct":"3","level":"3","hint":"","answer":"<p><span class=\"math-tex\">$\\log_{xyz}w=6$<\/span> ⇔ <span class=\"math-tex\">$\\log_w(xyz)=\\dfrac{1}{6}$<\/span><\/p><p>⇔ <span class=\"math-tex\">$\\log_wx+\\log_wy+\\log_wz=\\dfrac{1}{6}$<\/span><\/p><p>⇔ <span class=\"math-tex\">$\\dfrac{1}{12}+\\dfrac{1}{20}+\\log_wz=\\dfrac{1}{6}$<\/span><\/p><p>⇔ <span class=\"math-tex\">$\\log_wz=\\dfrac{1}{30}$<\/span><\/p><p>⇔ <span class=\"math-tex\">$\\log_zw=30$<\/span>.<\/p><p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>C.<\/strong> 30.<\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2024-03-31 04:13:35","option_type":"txt","len":1}]}