Bài ôn tập chương 6 - Tỉ lệ thức và đại lượng tỉ lệ-Bài tập dễ

Home Toán lớp 7 - Sách KNTT Bài ôn tập chương 6 - Tỉ lệ thức và đại lượng tỉ lệBài tập cơ bản

{"common":{"save":0,"post_id":"5800","level":1,"total":10,"point":10,"point_extra":0},"segment":[{"id":"8411","post_id":"5800","mon_id":"1158532","chapter_id":"1158659","question":"Ch\u1ecdn phát bi\u1ec3u \u0111úng<\/p>","options":["A.<\/strong> $\\dfrac{2}{5}: \\dfrac{3}{7}$<\/span> và (–14) : (–15) t\u1ea1o thành m\u1ed9t t\u1ec9 l\u1ec7 th\u1ee9c ","B.<\/strong> $\\dfrac{1}{2}:0,5$<\/span> và 1 : 4 t\u1ea1o thành m\u1ed9t t\u1ec9 l\u1ec7 th\u1ee9c"],"correct":"1","level":"1","hint":"","answer":"A.<\/strong> $\\dfrac{2}{5}: \\dfrac{3}{7}$<\/span> và (–14) : (–15) t\u1ea1o thành m\u1ed9t t\u1ec9 l\u1ec7 th\u1ee9c là phát bi\u1ec3u \u0111úng vì $\\dfrac{2}{5}:\\dfrac{3}{7}=\\dfrac{2}{5}.\\dfrac{7}{3}=\\dfrac{14}{15}$<\/span> và (–14) : (–15) = $\\dfrac{14}{15}$<\/span><\/p>B.<\/strong> $\\dfrac{1}{2}:0,5$<\/span> và 1 : 4 t\u1ea1o thành m\u1ed9t t\u1ec9 l\u1ec7 th\u1ee9c là phát bi\u1ec3u sai vì  $\\dfrac{1}{2}:0,5=\\dfrac{1}{2}:\\dfrac{1}{2}=\\dfrac{1}{2}.2=1$<\/span> và 1 : 4 = $\\dfrac{1}{4}$<\/span><\/p>\u0110áp án \u0111úng là   A.<\/strong> $\\dfrac{2}{5}: \\dfrac{3}{7}$<\/span> và (–14) : (–15) t\u1ea1o thành m\u1ed9t t\u1ec9 l\u1ec7 th\u1ee9c <\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"1","date":"2022-05-30 04:11:36","option_type":"math","len":0},{"id":"8413","post_id":"5800","mon_id":"1158532","chapter_id":"1158659","question":"Tìm m\u1ed1i quan h\u1ec7 gi\u1eefa hai \u0111\u1ea1i l\u01b0\u1ee3ng x và y v\u1edbi các giá tr\u1ecb \u0111\u01b0\u1ee3c cho trong b\u1ea3ng d\u01b0\u1edbi \u0111ây:<\/p><table border=\"1\" cellpadding=\"1\" cellspacing=\"1\" style=\"height: 100px; width: 200px;\"><tbody> <tr> <td>x<\/td> <td>–3<\/td> <td>1,2<\/td> <td>–18<\/td> <\/tr> <tr> <td>y<\/td> <td>–0,5<\/td> <td>0,2<\/td> <td>–3<\/td> <\/tr><\/tbody><\/table>","options":["A.<\/strong> y t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi x theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 là 6","B.<\/strong> y t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi x theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 là $\\dfrac{1}{6}$<\/span>","C. <\/strong>y t\u1ec9 l\u1ec7 ngh\u1ecbch v\u1edbi x theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 là 6","D.<\/strong> y t\u1ec9 l\u1ec7 ngh\u1ecbch v\u1edbi x theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 là $\\dfrac{1}{6}$<\/span>"],"correct":"2","level":"1","hint":"","answer":"D\u1ef1a vào b\u1ea3ng ta có<\/p>$\\dfrac{-0,5}{-3}=\\dfrac{1}{6} ; \\dfrac{0,2}{1,2}= \\dfrac{1}{6} ; \\dfrac{-3}{-18} =\\dfrac{1}{6}$<\/span>  <\/p>⇒ $\\dfrac{-0,5}{-3}=\\dfrac{0,2}{1,2}=\\dfrac{-3}{-18}$<\/span> $\\left( = \\dfrac{1}{6} \\right)$<\/span><\/p>Do \u0111ó  y t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi x theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 là $\\dfrac{1}{6}$<\/span> .<\/p>\u0110áp án \u0111úng là   B.<\/strong> y t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi x theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 là $\\dfrac{1}{6}$<\/span><\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"1","date":"2022-05-30 04:22:59","option_type":"math","len":0},{"id":"8414","post_id":"5800","mon_id":"1158532","chapter_id":"1158659","question":"Tìm x trong t\u1ec9 l\u1ec7 th\u1ee9c sau<\/p>$\\dfrac{x}{2}=\\dfrac{-20}{5}$<\/span><\/p>","options":["A.<\/strong> x = –5","B.<\/strong> x = –8","C.<\/strong> x = 8","D.<\/strong> x = 5"],"correct":"2","level":"1","hint":"","answer":"Vì  $\\dfrac{x}{2}=\\dfrac{-20}{5}$<\/span>  nên  x = $\\dfrac{2 . (-20)}{5}$<\/span> = –8<\/p>\u0110áp án \u0111úng là    B.<\/strong> x = –8<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"1","date":"2022-05-30 04:28:40","option_type":"txt","len":1}]}