{"common":{"save":0,"post_id":"7048","level":1,"total":10,"point":10,"point_extra":0},"segment":[{"id":"4851","post_id":"7048","mon_id":"1158924","chapter_id":"1159147","question":"<p>Cho m\u1ed9t c\u1ea5p s\u1ed1 c\u1ed9ng c&oacute;&nbsp;<span class=\"math-tex\">$u_1=-3;u_2=3$<\/span>. T&igrave;m d.<\/p>","options":["<strong>A.<\/strong> d = 5","<strong>B.<\/strong> d = 7","<strong>C.<\/strong> d = 6","<strong>D.<\/strong> d = 0"],"correct":"3","level":"1","hint":"","answer":"<p>Ta c&oacute;:&nbsp;<\/p><p>d =&nbsp;<span class=\"math-tex\">$u_2-u_1=3-(-3)=6$<\/span><\/p><p>Ch\u1ecdn&nbsp;<span style=\"color:#16a085;\"><strong>C.<\/strong>&nbsp;d = 6<\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2023-12-06 01:37:11","option_type":"txt","len":0},{"id":"4852","post_id":"7048","mon_id":"1158924","chapter_id":"1159147","question":"<p>T&igrave;m s\u1ed1 xen gi\u1eefa hai s\u1ed1 2 v&agrave; 22 \u0111\u1ec3 \u0111\u01b0\u1ee3c c\u1ea5p s\u1ed1 c\u1ed9ng c&oacute; 3 s\u1ed1 h\u1ea1ng.<\/p>","options":["<strong>A.<\/strong> 12","<strong>B.<\/strong> 10","<strong>C.<\/strong> 14","<strong>D.<\/strong> 8"],"correct":"1","level":"1","hint":"","answer":"<p>G\u1ecdi s\u1ed1 c\u1ea7n t&igrave;m l&agrave; x.<\/p><p>Ba s\u1ed1 2, x, 22 l\u1eadp th&agrave;nh c\u1ea5p s\u1ed1 c\u1ed9ng n&ecirc;n x =&nbsp;<span class=\"math-tex\">$\\dfrac{2+22}{2}=12$<\/span><\/p><p>Ch\u1ecdn&nbsp;<span style=\"color:#16a085;\"><strong>A.<\/strong> 12<\/span><span style=\"color:#16a085;\"><\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2023-12-06 01:41:08","option_type":"txt","len":0},{"id":"4853","post_id":"7048","mon_id":"1158924","chapter_id":"1159147","question":"<p>Cho c\u1ea5p s\u1ed1 c\u1ed9ng <span class=\"math-tex\">$(u_n)$<\/span>&nbsp;c&oacute; <span class=\"math-tex\">$u_1=-3,u_6=27$<\/span>.&nbsp;T&iacute;nh c&ocirc;ng sai d.<\/p>","options":["<strong>A.<\/strong> d = 5","<strong>B.<\/strong> d = 6","<strong>C.<\/strong> d = 7","<strong>D.<\/strong> d = 8"],"correct":"2","level":"1","hint":"<p>&Aacute;p d\u1ee5ng&nbsp;c&ocirc;ng th\u1ee9c s\u1ed1 h\u1ea1ng t\u1ed5ng qu&aacute;t c\u1ee7a c\u1ea5p s\u1ed1 c\u1ed9ng&nbsp;<span class=\"math-tex\">$u_n=u_1+(n-1).d$<\/span><\/p>","answer":"<p>&Aacute;p d\u1ee5ng&nbsp;c&ocirc;ng th\u1ee9c s\u1ed1 h\u1ea1ng t\u1ed5ng qu&aacute;t c\u1ee7a c\u1ea5p s\u1ed1 c\u1ed9ng&nbsp;<span class=\"math-tex\">$u_n=u_1+(n-1).d$<\/span>, ta c&oacute;:<\/p><p><span class=\"math-tex\">$u_6=u_1+5d$<\/span><\/p><p><span class=\"math-tex\">$\\Leftrightarrow 27=-3+5d$<\/span><\/p><p><span class=\"math-tex\">$\\Leftrightarrow d=6$<\/span><\/p><p>Ch\u1ecdn&nbsp;<span style=\"color:#16a085;\"><strong>B.<\/strong>&nbsp;d = 6<\/span><\/p>","type":"choose","extra_type":"classic","user_id":"131","test":"0","date":"2023-12-06 01:42:39","option_type":"txt","len":0}]}