Chú ý: Để đảm bảo quyền lợi và bảo vệ tài khoản của mình
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{"common":{"save":0,"post_id":"4767","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"7881","post_id":"4767","mon_id":"1158113","chapter_id":"1158119","question":"<p>Tìm s\u1ed1 nguyên x th\u1ecfa mãn<\/p><p><span class=\"math-tex\">$\\dfrac{-1}{4}<\\dfrac{x}{40}<\\dfrac{-1}{5}$<\/span><\/p><p>\u0110áp s\u1ed1 x = <input class=\"tim_x input_number\" tpl=\"dien_so\" type=\"text\"\/><\/p>","options":"","correct":["[\"-9\"]"],"level":"3","hint":"<p>Tìm m\u1eabu s\u1ed1 chung c\u1ee7a các phân s\u1ed1 trên \u0111\u1ec3 quy \u0111\u1ed3ng m\u1eabu s\u1ed1, r\u1ed3i so sánh.<\/p>","answer":"<p>MC là 40<\/p><p><span class=\"math-tex\">$\\dfrac{-1}{4}=\\dfrac{-10}{40}$<\/span> ; <span class=\"math-tex\">$\\dfrac{-1}{5}=\\dfrac{-8}{40}$<\/span><\/p><p>So sánh <span class=\"math-tex\">$\\dfrac{-10}{40}< \\dfrac{x}{40}<\\dfrac{-8}{40}$<\/span><\/p><p>Xét t\u1eed có -10 < x < -8 mà x là s\u1ed1 nguyên nên x = -9.<\/p><p>\u0110áp án c\u1ea7n \u0111i\u1ec1n là <strong><span style=\"color:#16a085;\">-<\/span><span style=\"color:#16a085;\">9<\/span><\/strong>.<\/p>","type":"blank","extra_type":"","time":"0","user_id":"131","test":"1","date":"2021-09-30 13:27:14"},{"id":"7917","post_id":"4767","mon_id":"1158113","chapter_id":"1158119","question":"<p>So sánh hai phân s\u1ed1 sau (\u0111i\u1ec1n d\u1ea5u <strong>> , < , =<\/strong> )<\/p><p><span class=\"math-tex\">$\\dfrac{-2^3.3^5}{-8^2.3^4.2019}$<\/span> <input class=\"tim_x input_number\" tpl=\"dien_so\" type=\"text\"\/> <span class=\"math-tex\">$\\dfrac{-2^5.3^4}{2021.9^4.5^2}$<\/span><\/p>","options":"","correct":["[\">\"]"],"level":"3","hint":"<p>So sánh hai phân s\u1ed1 v\u1edbi s\u1ed1 0.<\/p>","answer":"<p>Ta có: <span class=\"math-tex\">$\\dfrac{-2^3.3^5}{-8^2.3^4.2019}$<\/span> > 0 (t\u1eed và m\u1eabu cùng d\u1ea5u )<\/p><p> <span class=\"math-tex\">$\\dfrac{-2^5.3^4}{2021.9^4.5^2}$<\/span> < 0 (t\u1eed và m\u1eabu trái d\u1ea5u)<\/p><p>Do \u0111ó <span class=\"math-tex\">$\\dfrac{-2^3.3^5}{-8^2.3^4.2019}$<\/span> <strong><span style=\"color:#16a085;\">> <\/span><\/strong><span class=\"math-tex\">$\\dfrac{-2^5.3^4}{2021.9^4.5^2}$<\/span><\/p><p>V\u1eady d\u1ea5u c\u1ea7n \u0111i\u1ec1n là <strong><span style=\"color:#16a085;\">><\/span><\/strong><\/p>","type":"blank","extra_type":"","time":"0","user_id":"131","test":"1","date":"2021-10-01 05:45:59"},{"id":"7920","post_id":"4767","mon_id":"1158113","chapter_id":"1158119","question":"<p>Có bao nhiêu s\u1ed1 nguyên x th\u1ecfa mãn<\/p><p><span class=\"math-tex\">$\u200b\u200b\\dfrac{-1}{9}<\\dfrac{x}{18}<\\dfrac{1}{2}$<\/span> ?<\/p>","options":["9","10","11","12"],"correct":"2","level":"3","hint":"<p>Quy \u0111\u1ed3ng m\u1eabu các phân s\u1ed1 \u0111\u1ec3 tìm x.<\/p>","answer":"<p>Ta có: <span class=\"math-tex\">$\\dfrac{-1}{9}=\\dfrac{-2}{18}$<\/span> ; <span class=\"math-tex\">$\\dfrac{1}{2}=\\dfrac{9}{18}$<\/span><\/p><p>Theo \u0111\u1ec1 bài ta có: <span class=\"math-tex\">$\\dfrac{-2}{18}< \\dfrac{x}{18}<\\dfrac{9}{18}$<\/span><\/p><p>Suy ra -2 < x < 9 mà x là s\u1ed1 nguyên nên x ∈ {-1 ; 0 ; 1 ; 2 ; 3 ; 4 ; 5 ; 6 ; 7 ; 8}<\/p><p>Do \u0111ó có <span style=\"color:#16a085;\">10 s\u1ed1 nguyên<\/span> th\u1ecfa mãn yêu c\u1ea7u.<\/p><p>\u0110áp án \u0111úng là <strong><span style=\"color:#16a085;\">10<\/span><\/strong><\/p>","type":"choose","extra_type":"star","time":"0","user_id":"131","test":"1","date":"2021-10-01 05:52:29","option_type":"txt","len":0}]}