Đường thẳng đi qua hai điểm-level3

Home Lớp 6 Toán lớp 6 - Sách kết nối tri thức Đường thẳng đi qua hai điểmBài tập nâng cao

{"common":{"save":0,"post_id":"825","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"1941","post_id":"825","mon_id":"0","chapter_id":"0","question":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","options":{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank_random","correct":[[["66"]]],"list":[{"point":10,"width":50,"content":"","type_input":"","ques":"Cho tr\u01b0\u1edbc 12 \u0111i\u1ec3m trong \u0111\u00f3 kh\u00f4ng c\u00f3 3 \u0111i\u1ec3m n\u00e0o th\u1eb3ng h\u00e0ng. V\u1ebd c\u00e1c \u0111\u01b0\u1eddng th\u1eb3ng \u0111i qua c\u00e1c c\u1eb7p \u0111i\u1ec3m. H\u1ecfi v\u1ebd \u0111\u01b0\u1ee3c t\u1ea5t c\u1ea3 bao nhi\u00eau \u0111\u01b0\u1eddng th\u1eb3ng? <br\/> \u0110\u00e1p \u00e1n l\u00e0: _input_ \u0111\u01b0\u1eddng th\u1eb3ng ","hint":"","explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> L\u1ea5y m\u1ed9t \u0111i\u1ec3m n\u1ed1i v\u1edbi n - 1 \u0111i\u1ec3m kh\u00e1c ta \u0111\u01b0\u1ee3c n - 1 \u0111\u01b0\u1eddng th\u1eb3ng <br\/> Qua n \u0111i\u1ec3m trong \u0111\u00f3 kh\u00f4ng c\u00f3 3 \u0111i\u1ec3m n\u00e0o th\u1eb3ng h\u00e0ng v\u1ebd \u0111\u01b0\u1ee3c: <br\/> $\\dfrac{n . (n - 1)}{2}$ \u0111\u01b0\u1eddng th\u1eb3ng <br\/> (V\u00ec m\u1ed7i \u0111\u01b0\u1eddng th\u1eb3ng \u0111\u00e3 \u0111\u01b0\u1ee3c t\u00ednh 2 l\u1ea7n n\u00ean ta ph\u1ea3i \u0111em k\u1ebft qu\u1ea3 chia 2) <\/span> <br\/><br\/> B\u00e0i gi\u1ea3i: <\/span><br\/> Qua hai \u0111i\u1ec3m lu\u00f4n v\u1ebd \u0111\u01b0\u1ee3c 1 \u0111\u01b0\u1eddng th\u1eb3ng <br\/> Qua 12 \u0111i\u1ec3m v\u1ebd \u0111\u01b0\u1ee3c t\u1ea5t c\u1ea3 s\u1ed1 \u0111\u01b0\u1eddng th\u1eb3ng l\u00e0: <br\/> $\\dfrac{12 . (12 - 1)}{2} = 66$ (\u0111\u01b0\u1eddng th\u1eb3ng) <br\/> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n l\u00e0: 66 <\/span> <br\/> L\u01b0u \u00fd: +) Sai l\u1ea7m hay m\u1eafc ph\u1ea3i khi l\u00e0m b\u00e0i to\u00e1n d\u1ea1ng n\u00e0y l\u00e0 khi t\u00ednh s\u1ed1 \u0111\u01b0\u1eddng th\u1eb3ng v\u1ebd \u0111\u01b0\u1ee3c ta kh\u00f4ng \u0111em k\u1ebft qu\u1ea3 chia 2 <br\/> +) Khi b\u00e0i to\u00e1n cho n \u0111i\u1ec3m m\u00e0 kh\u00f4ng n\u00f3i g\u00ec th\u00eam ta hi\u1ec3u \u0111\u00f3 l\u00e0 \u0111i\u1ec3m ph\u00e2n bi\u1ec7t<\/span> "}]}]},"correct":"","level":"3","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:14:56"},{"id":"1942","post_id":"825","mon_id":"0","chapter_id":"0","question":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","options":{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank_random","correct":[[["132"]]],"list":[{"point":10,"width":50,"content":"","type_input":"","ques":"Gi\u1ea3i b\u00f3ng \u0111\u00e1 v\u00f4 \u0111\u1ecbch qu\u1ed1c gia h\u1ea1ng chuy\u00ean nghi\u1ec7p c\u00f3 12 \u0111\u1ed9i tham gia \u0111\u1ea5u v\u00f2ng tr\u00f2n 2 l\u01b0\u1ee3t \u0111i v\u00e0 v\u1ec1. T\u00ednh t\u1ed5ng s\u1ed1 tr\u1eadn \u0111\u1ea5u? <br\/> \u0110\u00e1p \u00e1n l\u00e0: _input_ tr\u1eadn \u0111\u1ea5u ","hint":"M\u1ed7i \u0111\u1ed9i \u0111\u1ec1u \u0111\u1ea5u v\u1edbi 1 \u0111\u1ed9i kh\u00e1c 2 l\u01b0\u1ee3t \u0111i v\u00e0 v\u1ec1 n\u00ean m\u1ed7i \u0111\u1ed9i \u0111\u1ec1u \u0111\u1ea5u v\u1edbi 1 \u0111\u1ed9i kh\u00e1c 2 tr\u1eadn \u0111\u1ea5u","explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1: <\/b> T\u00ednh s\u1ed1 tr\u1eadn \u0111\u1ea5u 1 \u0111\u1ed9i \u0111\u1ea5u v\u1edbi 11 \u0111\u1ed9i c\u00f2n l\u1ea1i <br\/> B\u01b0\u1edbc 2: <\/b> T\u00ednh s\u1ed1 tr\u1eadn \u0111\u1ea5u c\u00e1c \u0111\u1ed9i \u0111\u1ea5u m\u00e0 12 \u0111\u1ed9i \u0111\u00e1 2 l\u01b0\u1ee3t \u0111i v\u00e0 v\u1ec1 <\/span> <br\/><br\/> B\u00e0i gi\u1ea3i: <\/span><br\/> N\u1ebfu g\u1ecdi 12 \u0111\u1ed9i b\u00f3ng \u0111\u00f3 l\u00e0 \u0111\u1ed9i 1, \u0111\u1ed9i 2, ..., \u0111\u1ed9i 12 <br\/> V\u00ec m\u1ed7i \u0111\u1ed9i \u0111\u1ec1u \u0111\u1ea5u v\u1edbi 1 \u0111\u1ed9i kh\u00e1c <br\/> S\u1ed1 tr\u1eadn \u0111\u1ea5u \u0111\u1ed9i 1 \u0111\u00e1 v\u1edbi 11 \u0111\u1ed9i c\u00f2n l\u1ea1i l\u00e0: 1. 11 = 11 (tr\u1eadn \u0111\u1ea5u) <br\/> 12 \u0111\u1ed9i s\u1ebd \u0111\u1ea5u t\u1ea5t c\u1ea3: 11 . 12 = 132 (tr\u1eadn \u0111\u1ea5u) <br\/> Trong \u0111\u00f3 m\u1ed7i \u0111\u1ed9i \u0111\u1ec1u \u0111\u00e3 \u0111\u00e1 v\u1edbi 11 \u0111\u1ed9i kh\u00e1c 2 l\u01b0\u1ee3t \u0111i v\u00e0 v\u1ec1 <br\/> V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n l\u00e0: 132 <\/span> <br\/> L\u01b0u \u00fd: <\/b> \u1ede b\u00e0i to\u00e1n n\u00e0y khi t\u00ednh s\u1ed1 tr\u1eadn \u0111\u1ea5u ta kh\u00f4ng chia 2 v\u00ec m\u1ed7i \u0111\u1ed9i \u0111\u1ec1u \u0111\u00e1 v\u1edbi 1 \u0111\u1ed9i kh\u00e1c 2 tr\u1eadn l\u01b0\u1ee3t \u0111i v\u00e0 v\u1ec1 <\/i><\/span> "}]}]},"correct":"","level":"3","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:14:56"},{"id":"1943","post_id":"825","mon_id":"0","chapter_id":"0","question":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","options":{"time":24,"part":[{"title":"\u0110i\u1ec1n \u0111\u00e1p \u00e1n \u0111\u00fang v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank_random","correct":[[["9"]]],"list":[{"point":10,"width":50,"content":"","type_input":"","ques":"Cho tr\u01b0\u1edbc m\u1ed9t s\u1ed1 \u0111i\u1ec3m trong \u0111\u00f3 kh\u00f4ng c\u00f3 3 \u0111i\u1ec3m n\u00e0o th\u1eb3ng h\u00e0ng. V\u1ebd c\u00e1c \u0111\u01b0\u1eddng th\u1eb3ng \u0111i qua c\u00e1c c\u1eb7p \u0111i\u1ec3m \u0111\u00f3. Bi\u1ebft t\u1ed5ng s\u1ed1 \u0111\u01b0\u1eddng th\u1eb3ng v\u1ebd \u0111\u01b0\u1ee3c l\u00e0 36 \u0111\u01b0\u1eddng th\u1eb3ng. T\u00ednh s\u1ed1 \u0111i\u1ec3m cho tr\u01b0\u1edbc \u0111\u00f3? <br\/> \u0110\u00e1p \u00e1n l\u00e0: _input_ \u0111i\u1ec3m","hint":"D\u1ef1a v\u00e0o c\u00f4ng th\u1ee9c $\\dfrac{n . (n - 1)}{2}$ \u0111\u1ec3 t\u00ednh s\u1ed1 \u0111i\u1ec3m, n ch\u00ednh l\u00e0 s\u1ed1 \u0111i\u1ec3m c\u1ea7n t\u00ecm. ","explain":" B\u00e0i gi\u1ea3i: <\/span><br\/> V\u00ec s\u1ed1 \u0111\u01b0\u1eddng th\u1eb3ng v\u1ebd \u0111\u01b0\u1ee3c qua n \u0111i\u1ec3m trong \u0111\u00f3 kh\u00f4ng c\u00f3 3 \u0111i\u1ec3m n\u00e0o kh\u00f4ng th\u1eb3ng h\u00e0ng l\u00e0: <br\/> $\\dfrac{n . (n - 1)}{2}$ <br\/> Bi\u1ebft s\u1ed1 \u0111\u01b0\u1eddng th\u1eb3ng v\u1ebd \u0111\u01b0\u1ee3c l\u00e0 36 \u0111\u01b0\u1eddng th\u1eb3ng n\u00ean ta c\u00f3: <br\/> $\\begin{align*} \\\\ \\dfrac{n . (n - 1)}{2} &= 36 \\\\ n . (n - 1) &= 36 . 2 \\\\ n . (n - 1) &= 72 \\\\ n . (n - 1) &= 9 . 8 \\end{align*}$ <br\/> $\\Rightarrow$ n = 9, n - 1 = 8 <br\/> V\u1eady c\u00f3 t\u1ea5t c\u1ea3 9 \u0111i\u1ec3m cho tr\u01b0\u1edbc <br\/> S\u1ed1 c\u1ea7n \u0111i\u1ec1n l\u00e0: 9 <\/span> <br\/> L\u01b0u \u00fd: V\u1edbi d\u1ea1ng b\u00e0i y\u00eau c\u1ea7u t\u00ecm n \u0111i\u1ec3m ph\u00e2n bi\u1ec7t trong \u0111\u00f3 kh\u00f4ng c\u00f3 3 \u0111i\u1ec3m n\u00e0o th\u1eb3ng h\u00e0ng bi\u1ebft s\u1ed1 \u0111\u01b0\u1eddng th\u1eb3ng v\u1ebd \u0111\u01b0\u1ee3c l\u00e0 a \u0111\u01b0\u1eddng th\u1eb3ng ta l\u00e0m nh\u01b0 sau: $\\dfrac{n . (n - 1)}{2} = a$ <br\/> Trong \u0111\u00f3 a l\u00e0 s\u1ed1 \u0111\u01b0\u1eddng th\u1eb3ng \u0111\u00e3 bi\u1ebft, n l\u00e0 s\u1ed1 \u0111i\u1ec3m c\u1ea7n t\u00ecm <\/i><\/span> "}]}]},"correct":"","level":"3","hint":"","answer":"","type":"json","extra_type":"","time":"0","user_id":"0","test":"0","date":"2019-09-30 09:14:56"}]}