Bội chung nhỏ nhất-level3

Home Lớp 6 Toán lớp 6 - Sách kết nối tri thức Bội chung nhỏ nhấtBài tập nâng cao

{"common":{"save":0,"post_id":"751","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"791","post_id":"751","mon_id":"0","chapter_id":"0","question":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","options":{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["25"]]],"list":[{"point":10,"width":60,"content":"","type_input":"","ques":"<center><img src='img\/4.jpg' \/><\/center> <br\/> T\u00ecm m\u1ed9t s\u1ed1 t\u1ef1 nhi\u00ean bi\u1ebft t\u00edch c\u1ee7a \u01b0\u1edbc s\u1ed1 l\u1edbn nh\u1ea5t v\u1edbi b\u1ed9i s\u1ed1 nh\u1ecf nh\u1ea5t kh\u00e1c 0 c\u1ee7a n\u00f3 l\u00e0 625 <br\/>S\u1ed1 \u0111\u00f3 l\u00e0: _input_ ","hint":"\u01af\u1edbc s\u1ed1 l\u1edbn nh\u1ea5t l\u00e0 ch\u00ednh n\u00f3, b\u1ed9i nh\u1ecf nh\u1ea5t kh\u00e1c 0 l\u00e0 ch\u00ednh n\u00f3","explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> \u01af\u1edbc s\u1ed1 l\u1edbn nh\u1ea5t c\u1ee7a a l\u00e0 a B\u1ed9i nh\u1ecf nh\u1ea5t kh\u00e1c 0 c\u1ee7a a c\u0169ng l\u00e0 a Khi \u0111\u00f3 t\u00edch l\u00e0: a . a = 625 <\/span> <br\/><br\/> B\u00e0i gi\u1ea3i:<\/span><br\/> G\u1ecdi s\u1ed1 c\u1ea7n t\u00ecm l\u00e0 a <br\/> \u01af\u1edbc s\u1ed1 l\u1edbn nh\u1ea5t c\u1ee7a a l\u00e0 a <br\/> B\u1ed9i s\u1ed1 nh\u1ecf nh\u1ea5t kh\u00e1c 0 c\u1ee7a a l\u00e0 a <br\/> T\u00edch c\u1ee7a \u01b0\u1edbc s\u1ed1 l\u1edbn nh\u1ea5t v\u1edbi b\u1ed9i s\u1ed1 nh\u1ecf nh\u1ea5t l\u00e0: <br\/> a . a = 625 = $5^4 = (45^2)^2 = 25^2$ $\\Rightarrow$ a = 25 <br\/> S\u1ed1 c\u1ea7n \u0111i\u1ec1n l\u00e0: 25 <\/span> "}]}]},"correct":"","level":"3","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:14:46"},{"id":"792","post_id":"751","mon_id":"0","chapter_id":"0","question":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","options":{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["34"]]],"list":[{"point":10,"width":60,"content":"","type_input":"","ques":"<center><img src='img\/13.jpg' \/><\/center> <br\/> T\u00ecm s\u1ed1 t\u1ef1 nhi\u00ean n sao cho n + 1 l\u00e0 \u01b0\u1edbc c\u1ee7a 105; n - 1 l\u00e0 b\u1ed9i c\u1ee7a 11. <br\/> S\u1ed1 \u0111\u00f3 l\u00e0: n = _input_ ","hint":"T\u00ecm t\u1eadp \u01af(105) r\u1ed3i t\u00ecm t\u1eadp c\u00e1c gi\u00e1 tr\u1ecb n, th\u1eed t\u1eebng gi\u00e1 tr\u1ecb c\u1ee7a n n\u1ebfu n - 1 t\u01b0\u01a1ng \u1ee9ng l\u00e0 b\u1ed9i c\u1ee7a 11 th\u00ec \u0111\u00f3 l\u00e0 s\u1ed1 c\u1ea7n t\u00ecm","explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1: <\/b> T\u00ecm t\u1eadp \u01af(105) <br\/> V\u00ec $(n + 1) \\in \u01af(105)$ n\u00ean ta t\u00ecm \u0111\u01b0\u1ee3c t\u1eadp c\u00e1c gi\u00e1 tr\u1ecb c\u1ee7a n <br\/> B\u01b0\u1edbc 2 : <\/b> Th\u1eed l\u1ea7n l\u01b0\u1ee3t c\u00e1c gi\u00e1 tr\u1ecb c\u1ee7a n \u0111\u1ec3 t\u00ecm n - 1 th\u1ecfa m\u00e3n l\u00e0 b\u1ed9i c\u1ee7a 11 <br\/> N\u1ebfu n - 1 $\\in B(11)$ th\u00ec gi\u00e1 tr\u1ecb \u0111\u00f3 c\u1ee7a n l\u00e0 s\u1ed1 c\u1ea7n t\u00ecm<\/span> <br\/><br\/> B\u00e0i gi\u1ea3i:<\/span><br\/>V\u00ec (n + 1) $\\in$ \u01af(105) n\u00ean ta c\u00f3: <br\/> (n + 1) $\\in$ \u01af(105) = {1; 3; 5; 7; 15; 21; 35; 105} <br\/> $\\Rightarrow$ n $\\in$ {0; 2; 4; 6; 14; 20; 34; 104} <br\/> V\u00ec n - 1 l\u00e0 b\u1ed9i c\u1ee7a 11 n\u00ean ta x\u00e9t t\u1eebng gi\u00e1 tr\u1ecb c\u1ee7a n <br\/> V\u1edbi n = 2 $\\Rightarrow $ n - 1 = 1 $\\not \\vdots$ 11 (lo\u1ea1i) <br\/> V\u1edbi n = 4 $\\Rightarrow$ n - 1 = 3 $\\not \\vdots$ 11 (lo\u1ea1i) <br\/> V\u1edbi n = 6 $\\Rightarrow$ n - 1 = 5 $\\not \\vdots$ 11 (lo\u1ea1i) <br\/> V\u1edbi n = 14 $\\Rightarrow$ n - 1 = 13 $\\not \\vdots$ 11 (lo\u1ea1i) <br\/> V\u1edbi n = 20 $\\Rightarrow$ n - 1 = 19 $\\not \\vdots$ 11 (lo\u1ea1i) <br\/> V\u1edbi n = 34 $\\Rightarrow$ n - 1 = 33 $\\vdots$ 11 (th\u1ecfa m\u00e3n) <\/b> <br\/> V\u1edbi n = 104 $\\Rightarrow$ n - 1 = 103 $\\not \\vdots$ 11 (lo\u1ea1i) <br\/> V\u1eady ch\u1ec9 c\u00f3 n = 34 l\u00e0 th\u1ecfa m\u00e3n n + 1 l\u00e0 \u01b0\u1edbc c\u1ee7a 105 v\u00e0 n - 1 l\u00e0 b\u1ed9i c\u1ee7a 11 <br\/> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n l\u00e0: 34 <\/span> "}]}]},"correct":"","level":"3","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:14:46"},{"id":"793","post_id":"751","mon_id":"0","chapter_id":"0","question":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","options":{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["841"]]],"list":[{"point":10,"width":60,"content":"","type_input":"","ques":"<center><img src='img\/12.jpg' \/><\/center> <br\/> T\u00ecm s\u1ed1 t\u1ef1 nhi\u00ean n l\u1edbn nh\u1ea5t c\u00f3 3 ch\u1eef s\u1ed1 sao cho n chia 17 d\u01b0 8, chia 25 d\u01b0 16 <br\/> S\u1ed1 \u0111\u00f3 l\u00e0: n = _input_ ","hint":"Ta \u0111i t\u00ecm s\u1ed1 t\u1ef1 nhi\u00ean n l\u1edbn nh\u1ea5t c\u00f3 3 ch\u1eef s\u1ed1 sao cho (n - 8) $\\vdots$ 17 v\u00e0 (n - 16) $\\vdots$ 25","explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1: <\/b>V\u00ec n chia 17 d\u01b0 8, chia 25 d\u01b0 16 n\u00ean: <br\/> (n - 8) $\\vdots$ 17 v\u00e0 (n - 16) $\\vdots$ 25 (n > 25) <br\/> B\u01b0\u1edbc 2 : <\/b> Bi\u1ebfn \u0111\u1ed5i t\u00ecm s\u1ed1 t\u1ef1 nhi\u00ean m sao cho (n + m) $\\vdots$ 17 v\u00e0 (n + m) $\\vdots$ 25 <br\/> Khi \u0111\u00f3 (n + m) $\\vdots$ BCNN(17; 25) <br\/> B\u01b0\u1edbc 3: <\/b> T\u00ecm c\u00e1c gi\u00e1 tr\u1ecb c\u1ee7a n <br\/> Ch\u1ecdn gi\u00e1 tr\u1ecb c\u1ee7a n th\u1ecfa m\u00e3n n l\u00e0 s\u1ed1 l\u1edbn nh\u1ea5t c\u00f3 3 ch\u1eef s\u1ed1 <\/span> <br\/><br\/> B\u00e0i gi\u1ea3i:<\/span><br\/> V\u00ec n chia 17 d\u01b0 8 n\u00ean (n - 8) $\\vdots$ 17 (n > 8) <br\/> $\\Rightarrow$ n = 17a + 8 ($a \\in \\mathbb{N}$) <br\/> $\\Rightarrow$ n + 9 $\\vdots$ 17 (1)<br\/> V\u00ec n chia 25 d\u01b0 16 n\u00ean (n - 16) $\\vdots$ 25 (n > 16) $\\Rightarrow$ n = 25b + 16 ($b \\in \\mathbb{N}$) <br\/> $\\Rightarrow$ (n + 9) $\\vdots$ 25 (2) <br\/> <br\/> T\u1eeb (1) v\u00e0 (2) $\\Rightarrow$ n + 9 $\\vdots$ BCNN(17; 25) <br\/> $\\Rightarrow$ (n + 9) $\\vdots$ 425 <br\/> $\\Rightarrow$ n = 425k - 9 ($k \\in \\mathbb{N}^*$) <br\/> V\u1edbi k = 1 $\\Rightarrow$ n = 425 . 1 - 9 = 416 <br\/> V\u1edbi k = 2 $\\Rightarrow$ n = 425 . 2 - 9 = 841 <br\/> V\u1edbi k = 3 $\\Rightarrow$ n = 425 . 3 - 9 = 1266 (lo\u1ea1i) <br\/> V\u00ec n l\u00e0 s\u1ed1 l\u1edbn nh\u1ea5t c\u00f3 3 ch\u1eef s\u1ed1 n\u00ean n = 841<br\/> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n l\u00e0: 841 <\/span> "}]}]},"correct":"","level":"3","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:14:46"}]}