Ôn tập chương 2 - Số thực - Bài tập nâng cao số 2

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{"common":{"save":0,"post_id":"5725","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"6979","post_id":"5725","mon_id":"1158532","chapter_id":"1158543","question":"Tìm x, bi\u1ebft:<\/p>| x + 3,4 | = 6,9 - 9,6<\/p><div class=\"lt123_imgs\"><img class=\"img_dd small\" src=\"\/data\/library\/gia-dinh\/2-ba-chau.png\" \/><\/div>","options":["A. <\/strong>x = 2,7","B. <\/strong>x = -6,1","C. <\/strong>x = -0,7 ho\u1eb7c x = -6,1","D. <\/strong>Không có giá tr\u1ecb c\u1ee7a x"],"correct":"4","level":"3","hint":"V\u1edbi m\u1ecdi s\u1ed1 th\u1ef1c x ta có: |x| $\\ge$<\/span> 0 (giá tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a m\u1ed9t s\u1ed1 th\u1ef1c x luôn là m\u1ed9t s\u1ed1 không âm)<\/p>","answer":"| x + 3,4 | = 6,9 - 9,6<\/p>| x + 3,4 | = -2,7<\/p>Vì -2,7 < 0 nên suy ra không có giá tr\u1ecb nào c\u1ee7a x th\u1ecfa mãn vì giá tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a m\u1ed9t s\u1ed1 luôn l\u1edbn h\u01a1n ho\u1eb7c b\u1eb1ng 0.<\/p>\u0110áp án \u0111úng là D. <\/strong>Không có giá tr\u1ecb c\u1ee7a x<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"1","date":"2022-04-08 10:05:56","option_type":"txt","len":2},{"id":"6980","post_id":"5725","mon_id":"1158532","chapter_id":"1158543","question":"Trong các kh\u1eb3ng \u0111\u1ecbnh sau, kh\u1eb3ng \u0111\u1ecbnh nào là \u0111úng?<\/p>","options":["A.<\/strong> $-\\sqrt{2} ; -\\sqrt{3};-\\sqrt{4}$<\/span><\/strong> là các s\u1ed1 th\u1ef1c","B.<\/strong> <\/strong>S\u1ed1 nguyên không là s\u1ed1 th\u1ef1c","C.<\/strong> <\/strong>S\u1ed1 0 v\u1eeba là s\u1ed1 vô t\u1ec9 v\u1eeba là s\u1ed1 h\u1eefu t\u1ec9","D.<\/strong> $-\\dfrac{2}{3} ; -4;-1,(23)$<\/span><\/strong> là các s\u1ed1 h\u1eefu t\u1ec9 âm"],"correct":"[\"1\",\"4\"]","level":"3","hint":"","answer":"A.<\/strong> $-\\sqrt{2} ; -\\sqrt{3};-\\sqrt{4}$<\/span><\/strong> là các s\u1ed1 th\u1ef1c              \u0110úng<\/p>B.<\/strong> <\/strong>S\u1ed1 nguyên không là s\u1ed1 th\u1ef1c                    Sai vì s\u1ed1 nguyên là s\u1ed1 th\u1ef1c<\/p>C.<\/strong> <\/strong>S\u1ed1 0 v\u1eeba là s\u1ed1 vô t\u1ec9 v\u1eeba là s\u1ed1 h\u1eefu t\u1ec9        Sai vì s\u1ed1 0 là s\u1ed1 h\u1eefu t\u1ec9, không ph\u1ea3i là s\u1ed1 vô t\u1ec9<\/p>D.<\/strong> $-\\dfrac{2}{3} ; -4;-1,(23)$<\/span><\/strong> là các s\u1ed1 h\u1eefu t\u1ec9 âm      \u0110úng<\/p>Các \u0111áp án \u0111úng là  A.<\/strong> $-\\sqrt{2} ; -\\sqrt{3};-\\sqrt{4}$<\/span><\/strong> là các s\u1ed1 th\u1ef1c  <\/span> và  D.<\/strong> $-\\dfrac{2}{3} ; -4;-1,(23)$<\/span><\/strong> là các s\u1ed1 h\u1eefu t\u1ec9 âm<\/span><\/p>","type":"checkbox","extra_type":"classic-checkbox","time":"0","user_id":"131","test":"1","date":"2022-04-10 01:42:34","option_type":"math","len":0},{"id":"6985","post_id":"5725","mon_id":"1158532","chapter_id":"1158543","question":"Ch\u1ecdn kh\u1eb3ng \u0111\u1ecbnh \u0111úng.<\/p><img class=\"img_dd small\" src=\"\/data\/library\/gia-dinh\/bo-con-2.png\" \/><\/p>","options":["A.<\/strong> Trên tr\u1ee5c s\u1ed1 th\u1ef1c, \u0111i\u1ec3m $-\\sqrt{3}$<\/span> n\u1eb1m tr\u01b0\u1edbc \u0111i\u1ec3m 0 ","B.<\/strong> Trên tr\u1ee5c s\u1ed1 th\u1ef1c, \u0111i\u1ec3m $-\\sqrt{3}$<\/span> n\u1eb1m sau \u0111i\u1ec3m $-\\sqrt{2}$<\/span> ","C.<\/strong> Trên tr\u1ee5c s\u1ed1 th\u1ef1c, \u0111i\u1ec3m $\\sqrt{3}$<\/span> n\u1eb1m tr\u01b0\u1edbc \u0111i\u1ec3m 0 ","D.<\/strong> Trên tr\u1ee5c s\u1ed1 th\u1ef1c, \u0111i\u1ec3m $\\sqrt{3}$<\/span> n\u1eb1m sau \u0111i\u1ec3m $\\sqrt{7}$<\/span> "],"correct":"1","level":"3","hint":"N\u1ebfu a ","answer":"A.<\/strong> Trên tr\u1ee5c s\u1ed1 th\u1ef1c, \u0111i\u1ec3m $-\\sqrt{3}$<\/span> n\u1eb1m tr\u01b0\u1edbc \u0111i\u1ec3m 0          \u0110úng<\/p>B.<\/strong> Trên tr\u1ee5c s\u1ed1 th\u1ef1c, \u0111i\u1ec3m $-\\sqrt{3}$<\/span> n\u1eb1m sau<\/span> \u0111i\u1ec3m $-\\sqrt{2}$<\/span>       Sai vì $-\\sqrt{3}<-\\sqrt{2}$<\/span> nên \u0111i\u1ec3m $-\\sqrt{3}$<\/span> n\u1eb1m tr\u01b0\u1edbc \u0111i\u1ec3m $-\\sqrt{2}$<\/span><\/p>C.<\/strong> Trên tr\u1ee5c s\u1ed1 th\u1ef1c, \u0111i\u1ec3m $\\sqrt{3}$<\/span> n\u1eb1m tr\u01b0\u1edbc<\/span> \u0111i\u1ec3m 0             Sai vì $\\sqrt{3}$<\/span> > 0 nên \u0111i\u1ec3m $\\sqrt{3}$<\/span>  n\u1eb1m sau \u0111i\u1ec3m 0<\/p>D.<\/strong> Trên tr\u1ee5c s\u1ed1 th\u1ef1c, \u0111i\u1ec3m $\\sqrt{3}$<\/span> n\u1eb1m sau<\/span> \u0111i\u1ec3m $\\sqrt{7}$<\/span>             Sai vì $\\sqrt{3}<\\sqrt{7}$<\/span>   nên \u0111i\u1ec3m $\\sqrt{3}$<\/span> n\u1eb1m tr\u01b0\u1edbc \u0111i\u1ec3m $\\sqrt{7}$<\/span><\/p>\u0110áp án \u0111úng là A.<\/strong> Trên tr\u1ee5c s\u1ed1 th\u1ef1c, \u0111i\u1ec3m $-\\sqrt{3}$<\/span> n\u1eb1m tr\u01b0\u1edbc \u0111i\u1ec3m 0 <\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"1","date":"2022-04-10 02:28:33","option_type":"math","len":0}]}