Toán lớp 7 - Sách kết nối tri thức - Đề kiểm tra 15 phút - Toán lớp 7 - Sách kết nối tri thức - Tháng 2 - Số 2

{"save":1,"level":1,"time":"15","total":10,"point":5,"segment":[{"id":"10268","test_id":"688","question":"<p>N\u1ebfu \u0111\u1ea1i l\u01b0\u1ee3ng y t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi \u0111\u1ea1i l\u01b0\u1ee3ng x theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 l&agrave; 3 v&agrave; \u0111\u1ea1i l\u01b0\u1ee3ng x t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi \u0111\u1ea1i l\u01b0\u1ee3ng z theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 l&agrave;&nbsp;&ndash;2 th&igrave; \u0111\u1ea1i l\u01b0\u1ee3ng y t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi \u0111\u1ea1i l\u01b0\u1ee3ng z theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 l&agrave;<\/p>","options":["<strong>A.<\/strong> 6","<strong>B.<\/strong> &ndash;6","<strong>C.<\/strong> 5","<strong>D.<\/strong> &ndash;1"],"correct":"2","answer":"<p>Ch\u1ecdn&nbsp;<span style=\"color:#16a085;\"><strong>B.<\/strong> &ndash;6.<\/span><\/p><p>V&igrave;&nbsp;\u0111\u1ea1i l\u01b0\u1ee3ng y t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi \u0111\u1ea1i l\u01b0\u1ee3ng x theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 l&agrave; 3 n&ecirc;n y = 3x.<\/p><p>V&igrave; \u0111\u1ea1i l\u01b0\u1ee3ng x t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi \u0111\u1ea1i l\u01b0\u1ee3ng z theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 l&agrave;&nbsp;&ndash;2 n&ecirc;n x =&nbsp;&ndash;2z.<\/p><p>T\u1eeb \u0111&oacute; suy ra y = 3x = 3. (&ndash;2z) =&nbsp;&ndash;6z.<\/p><p>V\u1eady \u0111\u1ea1i l\u01b0\u1ee3ng y t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi \u0111\u1ea1i l\u01b0\u1ee3ng z theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 l&agrave;&nbsp;<span style=\"color:#16a085;\"><strong>&ndash;6<\/strong><\/span>.<\/p>","type":"choose","user_id":"126","test":"1","date":"2025-08-03 20:03:22"},{"id":"10269","test_id":"688","question":"<p data-end=\"3404\" data-start=\"3221\">Bi\u1ebft hai \u0111\u1ea1i l\u01b0\u1ee3ng x v&agrave; y t\u1ec9 l\u1ec7 ngh\u1ecbch v&agrave; khi&nbsp;x = 4 th&igrave; y = 12. T&iacute;nh y khi x = 6.<\/p>","options":["<strong>A.<\/strong> 8","<strong>B.<\/strong> 10","<strong>C.<\/strong> 6","<strong>D.<\/strong> 12"],"correct":"1","answer":"<p>Ch\u1ecdn&nbsp;<span style=\"color:#16a085;\"><strong>A.<\/strong> 8.<\/span><\/p><p>Gi\u1ea3 s\u1eed x v&agrave; y t\u1ec9 l\u1ec7 ngh\u1ecbch v\u1edbi nhau theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 l&agrave; a.<\/p><p>V&igrave; khi x = 4 th&igrave; y = 12 n&ecirc;n a = x.y = 4.12 = 48.<\/p><p>Do \u0111&oacute;&nbsp;<span class=\"math-tex\">$y=\\dfrac{48}{x}$<\/span>.<\/p><p>V\u1eady khi&nbsp;<span class=\"math-tex\">$x=6$<\/span> th&igrave;&nbsp;<span class=\"math-tex\">$y=\\dfrac{48}{6}=8$<\/span>.<\/p>","type":"choose","user_id":"126","test":"1","date":"2025-08-03 20:04:16"}]}