{"common":{"save":0,"post_id":"7788","level":2,"total":10,"point":10,"point_extra":0},"segment":[{"id":"7334","post_id":"7788","mon_id":"1159278","chapter_id":"1159282","question":"<p>So sánh m và n bi\u1ebft <span class=\"math-tex\">$m-\\dfrac{1}{2}=n$<\/span>.<br \/>.<\/p>","options":["<strong>A.<\/strong> m < n","<strong>B.<\/strong> n <span class=\"math-tex\">$\\ge$<\/span> m","<strong>C.<\/strong> m <span class=\"math-tex\">$\\le$<\/span> n","<strong>D.<\/strong> m > n"],"correct":"4","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>D.<\/strong> m > n.<\/span><\/p><p>Cách 1. Ta có <span class=\"math-tex\">$-\\dfrac{1}{2}<0$<\/span> nên <span class=\"math-tex\">$m-\\dfrac{1}{2}< m$<\/span>, suy ra <span class=\"math-tex\">$n< m$<\/span> hay m > n.<\/p><p>Cách 2. Ta có <span class=\"math-tex\">$m-\\dfrac{1}{2}=n$<\/span> hay <span class=\"math-tex\">$m-n=\\dfrac{1}{2}$<\/span> > 0, suy ra <span class=\"math-tex\">$m > n$<\/span>.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2024-10-06 08:29:29","option_type":"math","len":0},{"id":"7336","post_id":"7788","mon_id":"1159278","chapter_id":"1159282","question":"<p>Ch\u1ecdn kh\u1eb3ng \u0111\u1ecbnh \u0111úng.<\/p>","options":["<strong>A.<\/strong> N\u1ebfu <span class=\"math-tex\">$\\begin{cases}a< b\\\\c > d\\end{cases}$<\/span> thì <span class=\"math-tex\">$a+b< c+d$<\/span>.","<strong>B.<\/strong> N\u1ebfu <span class=\"math-tex\">$\\begin{cases}a< b\\\\c > d\\end{cases}$<\/span> thì <span class=\"math-tex\">$ac= bd$<\/span>.","<strong>C.<\/strong> N\u1ebfu <span class=\"math-tex\">$\\begin{cases}a> b\\\\c > d\\end{cases}$<\/span> thì <span class=\"math-tex\">$ac< bd$<\/span>.","<strong>D.<\/strong> N\u1ebfu <span class=\"math-tex\">$\\begin{cases}a> b\\\\c > d\\end{cases}$<\/span> thì <span class=\"math-tex\">$a+c> b+d$<\/span>."],"correct":"4","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>D.<\/strong> N\u1ebfu <span class=\"math-tex\">$\\begin{cases}a> b\\\\c > d\\end{cases}$<\/span> thì <span class=\"math-tex\">$a+c> b+d$<\/span>.<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2024-10-06 08:32:27","option_type":"math","len":0},{"id":"7338","post_id":"7788","mon_id":"1159278","chapter_id":"1159282","question":"<p>Cho <span class=\"math-tex\">$-2x+3< -2y+3$<\/span>. So sánh x và y.<\/p>","options":["<strong>A.<\/strong> x > y","<strong>B.<\/strong> x < y","<strong>C.<\/strong> x <span class=\"math-tex\">$\\ge$<\/span> y","<strong>D.<\/strong> x <span class=\"math-tex\">$\\le$<\/span> y"],"correct":"1","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>A.<\/strong> x > y.<\/span><\/p><p>Theo \u0111\u1ec1 bài ta có:<br \/><span class=\"math-tex\">$-2x+3<-2y+3$<\/span><\/p><p><span class=\"math-tex\">$-\\dfrac{1}{2}(-2x+3)>-\\dfrac{1}{2}(-2y+3)$<\/span> (nhân hai v\u1ebf v\u1edbi <span class=\"math-tex\">$-\\dfrac{1}{2}$<\/span>, b\u1ea5t \u0111\u1eb3ng th\u1ee9c \u0111\u1ea3o chi\u1ec1u)<\/p><p><span class=\"math-tex\">$x-\\dfrac{3}{2}>y-\\dfrac{3}{2}$<\/span><\/p><p><span class=\"math-tex\">$x-\\dfrac{3}{2}+\\dfrac{3}{2}>y-\\dfrac{3}{2}+\\dfrac{3}{2}$<\/span> (c\u1ed9ng hai v\u1ebf v\u1edbi <span class=\"math-tex\">$\\dfrac{3}{2}$<\/span>, b\u1ea5t \u0111\u1eb3ng th\u1ee9c cùng chi\u1ec1u)<\/p><p><span class=\"math-tex\">$x> y$<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2024-10-06 08:39:23","option_type":"math","len":0}]}
