Cộng, trừ, nhân, chia số hữu tỉ

Home Lớp 7 Toán lớp 7 - Sách kết nối tri thức Bài 2: Cộng, trừ, nhân, chia số hữu tỉBài tập cơ bản

{"common":{"save":0,"post_id":"5641","level":1,"total":10,"point":10,"point_extra":0},"segment":[{"id":"6775","post_id":"5641","mon_id":"1158532","chapter_id":"1158544","question":"K\u1ebft qu\u1ea3 c\u1ee7a phép tính sau khi rút g\u1ecdn phân s\u1ed1 là:<\/p>$\\dfrac{-12}{15} + \\dfrac{12}{10} = $<\/span><input class=\"tim_x input_number\" type=\"text\" \/><\/span><input class=\"tim_x input_number\" type=\"text\" \/><\/span><\/span><\/p>","options":"","correct":["[\"2\",\"5\"]"],"level":"1","hint":"Ta có th\u1ec3 c\u1ed9ng tr\u1eeb hai s\u1ed1 h\u1eefu t\u1ec9 b\u1eb1ng cách vi\u1ebft chúng d\u01b0\u1edbi d\u1ea1ng phân s\u1ed1 r\u1ed3i áp d\u1ee5ng các quy t\u1eafc c\u1ed9ng, tr\u1eeb phân s\u1ed1.  <\/p>","answer":"Ta có: $\\dfrac{-12}{15} + \\dfrac{12}{10} $<\/span> $= \\dfrac{-4}{5} + \\dfrac{6}{5}$<\/span>  $=\\dfrac{-4+6}{5}$<\/span> $=\\dfrac{2}{5}$<\/span> V\u1eady các s\u1ed1 c\u1ea7n \u0111i\u1ec1n l\u1ea7n l\u01b0\u1ee3t là 2 và 5<\/span>  (phân s\u1ed1 $ \\dfrac{2}{5} $<\/span>)  <\/p>","type":"blank","extra_type":"","time":"0","user_id":"131","test":"3","date":"2022-03-29 07:09:27"},{"id":"6776","post_id":"5641","mon_id":"1158532","chapter_id":"1158544","question":"Tính:  $\\dfrac{-2}{7} - \\dfrac{3}{4} + \\dfrac{9}{7} - \\dfrac{1}{4} $<\/span> = <input class=\"_tit_hoi\" disabled=\"disabled\" type=\"text\"\/><\/p>","options":["1","2","0","3"],"correct":"3","level":"1","hint":"Phép c\u1ed9ng các s\u1ed1 h\u1eefu t\u1ec9 c\u0169ng có tính ch\u1ea5t giao hoán và k\u1ebft h\u1ee3p gi\u1ed1ng phép c\u1ed9ng phân s\u1ed1.  <\/p>","answer":"Ta có:      $\\dfrac{-2}{7} - \\dfrac{3}{4} + \\dfrac{9}{7} - \\dfrac{1}{4}$<\/span><\/p>Áp d\u1ee5ng tính ch\u1ea5t giao hoán, ta có: $=\\dfrac{-2}{7} + \\dfrac{9}{7} - \\dfrac{3}{4} - \\dfrac{1}{4}$<\/span> $=\\left( \\dfrac{-2}{7} + \\dfrac{9}{7} \\right) - \\left( \\dfrac{3}{4} + \\dfrac{1}{4} \\right)$<\/span> $= \\dfrac{7}{7} - \\dfrac{4}{4}$<\/span> =  1  -   1<\/p>=    0 \u0110áp án \u0111úng là 0<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"3","date":"2022-03-29 07:12:26","option_type":"number","len":0},{"id":"6777","post_id":"5641","mon_id":"1158532","chapter_id":"1158544","question":"K\u1ebft qu\u1ea3 c\u1ee7a phép tính $\\dfrac{3}{8} - \\dfrac{7}{16}$<\/span>  <\/p>","options":["A.<\/strong> $\\dfrac{-1}{16}$<\/span>","B.<\/strong> $\\dfrac{1}{16}$<\/span>","C.<\/strong> $\\dfrac{1}{8}$<\/span>","D.<\/strong> $\\dfrac{-1}{8}$<\/span>"],"correct":"1","level":"1","hint":"Ta có th\u1ec3 c\u1ed9ng tr\u1eeb hai s\u1ed1 h\u1eefu t\u1ec9 b\u1eb1ng cách vi\u1ebft chúng d\u01b0\u1edbi d\u1ea1ng phân s\u1ed1 r\u1ed3i áp d\u1ee5ng các quy t\u1eafc c\u1ed9ng, tr\u1eeb phân s\u1ed1.  <\/p>","answer":"Ta có:  $\\dfrac{3}{8} - \\dfrac{7}{16}$<\/span> $=\\dfrac{6}{16} - \\dfrac{7}{16}$<\/span> $=\\dfrac{6-7}{16} $<\/span> $= \\dfrac{-1}{16}$<\/span><\/p>\u0110áp án \u0111úng là  A.<\/strong> $\\dfrac{-1}{16}$<\/span><\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"3","date":"2022-03-29 07:15:29","option_type":"math","len":0}]}