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HomeLớp 9Toán lớp 9 - Sách Kết nối tri thứcBài 4. Phương trình quy về phương trình bậc nhất một ẩnBài tập trung bình
{"common":{"save":0,"post_id":"7780","level":2,"total":10,"point":10,"point_extra":0},"segment":[{"id":"7217","post_id":"7780","mon_id":"1159278","chapter_id":"1159282","question":"<p>Hai vòi n\u01b0\u1edbc cùng ch\u1ea3y vào b\u1ec3 thì sau 24 gi\u1edd \u0111\u1ea7y b\u1ec3. N\u1ebfu vòi th\u1ee9 nh\u1ea5t ch\u1ea3y 3 gi\u1edd, vòi th\u1ee9 hai ch\u1ea3y 6 gi\u1edd thì \u0111\u01b0\u1ee3c <span class=\"math-tex\">$\\dfrac{1}{3}$<\/span> b\u1ec3. N\u1ebfu g\u1ecdi x gi\u1edd là th\u1eddi gian vòi th\u1ee9 nh\u1ea5t ch\u1ea3y m\u1ed9t mình \u0111\u1ea7y b\u1ec3 thì s\u1ed1 ph\u1ea7n n\u01b0\u1edbc trong b\u1ec3 vòi th\u1ee9 hai ch\u1ea3y m\u1ed9t mình trong 6 gi\u1edd là<\/p>","options":["<strong>A.<\/strong> <span class=\"math-tex\">$\\dfrac{6}{x}+24.\\bigg(\\dfrac{1}{3}-\\dfrac{1}{x}\\bigg)$<\/span>","<strong>B.<\/strong> <span class=\"math-tex\">$6.\\bigg(\\dfrac{1}{24}-\\dfrac{1}{x}\\bigg)$<\/span>","<strong>C.<\/strong> <span class=\"math-tex\">$24.\\bigg(\\dfrac{1}{6}-\\dfrac{1}{x}\\bigg)$<\/span>","<strong>D.<\/strong> <span class=\"math-tex\">$\\dfrac{6}{x}+3.\\bigg(\\dfrac{1}{24}-\\dfrac{1}{x}\\bigg)$<\/span>"],"correct":"2","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>B.<\/strong> <span class=\"math-tex\">$6.\\bigg(\\dfrac{1}{24}-\\dfrac{1}{x}\\bigg)$<\/span><\/span><\/p><p>Th\u1eddi gian vòi th\u1ee9 nh\u1ea5t ch\u1ea3y m\u1ed9t mình \u0111\u1ea7y b\u1ec3 là x gi\u1edd<\/p><p>M\u1ed7i gi\u1edd vòi th\u1ee9 nh\u1ea5t ch\u1ea3y \u0111\u01b0\u1ee3c <span class=\"math-tex\">$\\dfrac{1}{x}$<\/span> b\u1ec3.<\/p><p>M\u1ed7i gi\u1edd c\u1ea3 hai vòi ch\u1ea3y \u0111\u01b0\u1ee3c <span class=\"math-tex\">$\\dfrac{1}{24}$<\/span> b\u1ec3<\/p><p>M\u1ed7i gi\u1edd vòi th\u1ee9 hai ch\u1ea3y \u0111\u01b0\u1ee3c <span class=\"math-tex\">$\\dfrac{1}{24}-\\dfrac{1}{x}$<\/span> b\u1ec3<\/p><p>S\u1ed1 ph\u1ea7n n\u01b0\u1edbc trong b\u1ec3 vòi th\u1ee9 hai ch\u1ea3y m\u1ed9t mình trong 6 gi\u1edd là <span style=\"color:#16a085;\"><span class=\"math-tex\">$6.\\bigg(\\dfrac{1}{24}-\\dfrac{1}{x}\\bigg)$<\/span><\/span>.<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2024-10-04 02:14:07","option_type":"math","len":0},{"id":"7218","post_id":"7780","mon_id":"1159278","chapter_id":"1159282","question":"<p>Hi\u1ec7n nay, m\u1eb9 Lan h\u01a1n Lan 20 tu\u1ed5i. Sau 5 n\u0103m n\u1eefa, n\u1ebfu s\u1ed1 tu\u1ed5i c\u1ee7a Lan là x (tu\u1ed5i) thì s\u1ed1 tu\u1ed5i c\u1ee7a m\u1eb9 Lan hi\u1ec7n nay là<\/p>","options":["<strong>A.<\/strong> x – 15","<strong>B.<\/strong> x + 25","<strong>C.<\/strong> x + 20","<strong>D.<\/strong> x + 15"],"correct":"4","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>D.<\/strong> x + 15<\/span><\/p><p>S\u1ed1 tu\u1ed5i c\u1ee7a Lan sau 5 n\u0103m là x (tu\u1ed5i).<\/p><p>S\u1ed1 tu\u1ed5i c\u1ee7a Lan hi\u1ec7n nay là x – 5 (tu\u1ed5i).<\/p><p>S\u1ed1 tu\u1ed5i c\u1ee7a m\u1eb9 Lan hi\u1ec7n nay là x – 5 + 20 = <span style=\"color:#16a085;\"><strong>x + 15 (tu\u1ed5i)<\/strong><\/span>.<\/p>","type":"choose","extra_type":"shape1","time":"0","user_id":"127","test":"0","date":"2024-10-04 02:16:34","option_type":"txt","len":0},{"id":"7220","post_id":"7780","mon_id":"1159278","chapter_id":"1159282","question":"<p>Nghi\u1ec7m c\u1ee7a ph\u01b0\u01a1ng trình <span class=\"math-tex\">$x^2-4x+4=0$<\/span> là<\/p>","options":["<strong>A.<\/strong> x = 2","<strong>B.<\/strong> x = –2","<strong>C.<\/strong> x = 4","<strong>D.<\/strong> x = –4"],"correct":"1","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>A.<\/strong> x = 2<\/span><\/p><p><span class=\"math-tex\">$x^2-4x+4=0$<\/span> hay <span class=\"math-tex\">$(x-2)^2=0$<\/span> suy ra x = 2.<\/p><p>V\u1eady nghi\u1ec7m c\u1ee7a ph\u01b0\u01a1ng trình <span class=\"math-tex\">$x^2-4x+4=0$<\/span> là x = 2.<\/p>","type":"choose","extra_type":"shape2","time":"0","user_id":"127","test":"0","date":"2024-10-04 02:18:39","option_type":"txt","len":0}]}