Toán lớp 7 - Sách kết nối tri thức - Đề kiểm tra 45 phút - Toán lớp 7 - Sách kết nối tri thức - Tháng 2 - Số 1
{"save":1,"level":1,"time":"45","total":25,"point":5,"segment":[{"id":"10278","test_id":"689","question":"<p data-end=\"3841\" data-start=\"3752\">Bi\u1ebft \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 là 4 và \u0111\u1ea1i l\u01b0\u1ee3ng x t\u1ec9 l\u1ec7 ngh\u1ecbch v\u1edbi \u0111\u1ea1i l\u01b0\u1ee3ng z theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 là 3. H\u1ecfi y và z t\u1ec9 l\u1ec7 thu\u1eadn hay t\u1ec9 l\u1ec7 ngh\u1ecbch và h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 là bao nhiêu?<\/p>","options":["<strong>A.<\/strong> y t\u1ec9 l\u1ec7 ngh\u1ecbch v\u1edbi z theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 là 12.","<strong>B.<\/strong> y t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi z theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 là 12.","<strong>C.<\/strong> y t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi z theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 là 7.","<p data-end=\"3892\" data-start=\"3843\"><strong>D.<\/strong> y t\u1ec9 l\u1ec7 ngh\u1ecbch v\u1edbi z theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 là 7.<\/p>"],"correct":"1","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>A.<\/strong> y t\u1ec9 l\u1ec7 ngh\u1ecbch v\u1edbi z theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 là 12.<\/span><\/p><p>Vì \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 là 4 nên <span class=\"math-tex\">$y=4x$<\/span>.<\/p><p>Vì \u0111\u1ea1i l\u01b0\u1ee3ng x t\u1ec9 l\u1ec7 ngh\u1ecbch v\u1edbi \u0111\u1ea1i l\u01b0\u1ee3ng z theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 là 3 nên <span class=\"math-tex\">$x=\\dfrac{3}{z}$<\/span>.<\/p><p>T\u1eeb \u0111ó suy ra <span class=\"math-tex\">$y=4x=4.\\dfrac{3}{z}=\\dfrac{12}{z}$<\/span> hay <span class=\"math-tex\">$y=\\dfrac{12}{z}$<\/span>.<\/p><p>V\u1eady y t\u1ec9 l\u1ec7 ngh\u1ecbch v\u1edbi z theo h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 là 12.<\/p>","type":"choose","user_id":"126","test":"1","date":"2025-08-03 20:20:42"},{"id":"10279","test_id":"689","question":"<p>B\u1ea1n An \u0111i t\u1eeb tr\u01b0\u1eddng v\u1ec1 nhà v\u1edbi v\u1eadn t\u1ed1c 12 km\/gi\u1edd h\u1ebft 30 phút. N\u1ebfu An \u0111i v\u1edbi v\u1eadn t\u1ed1c 10 km\/gi\u1edd thì h\u1ebft<\/p>","options":["<strong>A.<\/strong> 25 phút","<strong>B.<\/strong> 45 phút","<strong>C.<\/strong> 36 phút","<strong>D.<\/strong> 0,36 gi\u1edd"],"correct":"3","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>C.<\/strong> 36 phút.<\/span><\/p><p>\u0110\u1ed5i 30 phút = 0,5 gi\u1edd.<\/p><p>G\u1ecdi th\u1eddi gian An \u0111i t\u1eeb tr\u01b0\u1eddng \u0111\u1ebfn nhà v\u1edbi v\u1eadn t\u1ed1c 10 km\/h là x (h).<\/p><p>\u0110i\u1ec1u ki\u1ec7n x > 0.<\/p><p>Vì v\u1edbi cùng quãng \u0111\u01b0\u1eddng thì v\u1eadn t\u1ed1c và th\u1eddi gian là hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 ngh\u1ecbch nên <span class=\"math-tex\">$12.0,5=10.x$<\/span> suy ra <span class=\"math-tex\">$x=12.0,5:10=0,6\\;(h)$<\/span>.<\/p><p>\u0110\u1ed5i 0,6 gi\u1edd = 36 phút.<\/p><p>V\u1eady An \u0111i t\u1eeb tr\u01b0\u1eddng v\u1ec1 nhà v\u1edbi v\u1eadn t\u1ed1c 10 km\/gi\u1edd h\u1ebft 36 phút.<\/p>","type":"choose","user_id":"126","test":"1","date":"2025-08-03 20:22:18"}]}