{"common":{"save":0,"post_id":"7109","level":2,"total":10,"point":10,"point_extra":0},"segment":[{"id":"5480","post_id":"7109","mon_id":"1158924","chapter_id":"1159168","question":"<p>V\u1edbi các s\u1ed1 th\u1ef1c d\u01b0\u01a1ng a, b b\u1ea5t kì. M\u1ec7nh \u0111\u1ec1 nào d\u01b0\u1edbi \u0111ây là <strong>\u0111úng<\/strong>?<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$\\log(ab)=\\log a.\\log b$<\/span>","<strong>B.<\/strong> <span class=\"math-tex\">$\\log\\dfrac{a}{b}=\\dfrac{\\log a}{\\log b}$<\/span>","<strong>C.<\/strong> <span class=\"math-tex\">$\\log(ab)=\\log a+\\log b$<\/span>","<strong>D.<\/strong> <span class=\"math-tex\">$\\log\\dfrac{a}{b}=\\log b -\\log a$<\/span>"],"correct":"3","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>C.<\/strong> <span class=\"math-tex\">$\\log(ab)=\\log a+\\log b$<\/span>.<\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2024-04-07 05:15:53","option_type":"math","len":0},{"id":"5482","post_id":"7109","mon_id":"1158924","chapter_id":"1159168","question":"<p>V\u1edbi m\u1ecdi s\u1ed1 th\u1ef1c d\u01b0\u01a1ng a, b, x, y và <span class=\"math-tex\">$a,b\\ne1$<\/span>. M\u1ec7nh \u0111\u1ec1 nào sau \u0111ây là <strong>sai<\/strong>?<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$\\log_a\\dfrac{1}{x}=\\log_ax$<\/span>","<strong>B.<\/strong> <span class=\"math-tex\">$\\log_a(xy)=\\log_ax+\\log_ay$<\/span>","<strong>C.<\/strong> <span class=\"math-tex\">$\\log_ba.\\log_ax=\\log_bx$<\/span>","<strong>D.<\/strong> <span class=\"math-tex\">$\\log_a\\dfrac{x}{y}=\\log_ax-\\log_ay$<\/span>"],"correct":"1","level":"2","hint":"","answer":"<p>Câu sai là <span style=\"color:#16a085;\"><strong>A.<\/strong> <span class=\"math-tex\">$\\log_a\\dfrac{1}{x}=\\log_ax$<\/span>.<\/span><\/p><p>Vì <span class=\"math-tex\">$\\log_a\\dfrac{1}{x}=-\\log_ax$<\/span>.<\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2024-04-07 05:19:29","option_type":"math","len":0},{"id":"5483","post_id":"7109","mon_id":"1158924","chapter_id":"1159168","question":"<p>Bác An g\u1eedi ti\u1ebft ki\u1ec7m ngân hàng <span class=\"math-tex\">$100.10^6$<\/span> \u0111\u1ed3ng kì h\u1ea1n 12 tháng v\u1edbi lãi su\u1ea5t không \u0111\u1ed5i là 6% m\u1ed9t n\u0103m. Khi \u0111ó sau n n\u0103m g\u1eedi thì t\u1ed5ng s\u1ed1 ti\u1ec1n bác An thu \u0111\u01b0\u1ee3c (c\u1ea3 v\u1ed1n l\u1eabn lãi) cho b\u1edfi công th\u1ee9c <span class=\"math-tex\">$A=100.10^6(1+0,06)^n$<\/span> \u0111\u1ed3ng. H\u1ecfi sau ít nh\u1ea5t bao nhiêu n\u0103m thì t\u1ed5ng s\u1ed1 ti\u1ec1n bác An thu \u0111\u01b0\u1ee3c không d\u01b0\u1edbi <span class=\"math-tex\">$150.10^6$<\/span> \u0111\u1ed3ng?<\/p>","options":["<strong>A.<\/strong> 7","<strong>B.<\/strong> 8","<strong>C.<\/strong> 9","<strong>D.<\/strong> 10"],"correct":"1","level":"2","hint":"","answer":"<p>Theo gi\u1ea3 thi\u1ebft ta có <span class=\"math-tex\">$100.10^6(1+0,06)^n\\ge150.10^6$<\/span><\/p><p>⇒ <span class=\"math-tex\">$n\\ge\\log_{1,06}1,5\\approx6,96$<\/span>.<\/p><p>V\u1eady sau ít nh\u1ea5t 7 n\u0103m thì bác An nh\u1eadn \u0111\u01b0\u1ee3c s\u1ed1 ti\u1ec1n không d\u01b0\u1edbi <span class=\"math-tex\">$150.10^6$<\/span> \u0111\u1ed3ng.<\/p><p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>A.<\/strong> 7.<\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2024-04-07 05:26:14","option_type":"txt","len":0}]}
