Bài tập cơ bản bài Nhân hai số nguyên cùng dấu. Nhân hai số nguyên khác dấu. Tính chất của phép nhân

Home Lớp 6 Toán lớp 6 sách cũ Nhân hai số nguyên cùng dấu. Nhân hai số nguyên khác dấu. Tính chất của phép nhân

Nhân hai số nguyên cùng dấu. Nhân hai số nguyên khác dấu. Tính chất của phép nhân

{"segment":[{"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":[[["-1080"]]],"list":[{"point":5,"width":60,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/daiso/bai26/lv1/img\/2.jpg' \/><\/center>(-135) . 8= _input_","hint":"","explain":"H\u01b0\u1edbng d\u1eabn:<\/span><br\/>Mu\u1ed1n nh\u00e2n hai s\u1ed1 nguy\u00ean kh\u00e1c d\u1ea5u, ta nh\u00e2n hai gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a ch\u00fang r\u1ed3i \u0111\u1eb7t d\u1ea5u (-) tr\u01b0\u1edbc k\u1ebft qu\u1ea3 nh\u1eadn \u0111\u01b0\u1ee3c<\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/> $\\begin{align*}(-135) . 8&= -(135 . 8)\\\\&= -1080\\end{align*}$<br\/>V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0: -1080<\/span><\/span> <br\/> "}]}],"id_ques":1231},{"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":[[["-856"]]],"list":[{"point":5,"width":60,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/daiso/bai26/lv1/img\/2.jpg' \/><\/center>(-214) . 4= _input_","hint":"","explain":"H\u01b0\u1edbng d\u1eabn:<\/span><br\/>Mu\u1ed1n nh\u00e2n hai s\u1ed1 nguy\u00ean kh\u00e1c d\u1ea5u, ta nh\u00e2n hai gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a ch\u00fang r\u1ed3i \u0111\u1eb7t d\u1ea5u (-) tr\u01b0\u1edbc k\u1ebft qu\u1ea3 nh\u1eadn \u0111\u01b0\u1ee3c<\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/> $\\begin{align*}(-214) . 4&= -(214 . 4)\\\\&= -856\\end{align*}$<br\/>V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0: -856<\/span><\/span> <br\/> "}]}],"id_ques":1232},{"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":[[["-690"]]],"list":[{"point":5,"width":60,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/daiso/bai26/lv1/img\/5.jpg' \/><\/center>138 . (-5)= _input_","hint":"","explain":"H\u01b0\u1edbng d\u1eabn:<\/span><br\/>Mu\u1ed1n nh\u00e2n hai s\u1ed1 nguy\u00ean kh\u00e1c d\u1ea5u, ta nh\u00e2n hai gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a ch\u00fang r\u1ed3i \u0111\u1eb7t d\u1ea5u (-) tr\u01b0\u1edbc k\u1ebft qu\u1ea3 nh\u1eadn \u0111\u01b0\u1ee3c<\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/> $\\begin{align*}138 . (-5)&= -(138 . 5)\\\\&= -690\\end{align*}$<br\/>V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0: -690<\/span><\/span> <br\/> "}]}],"id_ques":1233},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":" T\u00ednh nhanh:<br\/>(-3) . (-15) = ?<\/span>","select":["A. -45","B. 55","C. 45","D. -55"],"hint":"","explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/>Mu\u1ed1n nh\u00e2n hai s\u1ed1 nguy\u00ean \u00e2m, ta nh\u00e2n hai gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a ch\u00fang.<\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3:<br\/>(-3) . (-15) = 3 . 15 = 45<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u0111\u00fang l\u00e0: C. 45<\/span><\/span> <br\/>","column":2}]}],"id_ques":1234},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" T\u00ednh nhanh:<br\/>(-8) . (-4) = ?<\/span>","select":["A. 32","B. -32","C. -36","D. -40"],"hint":"","explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/>Mu\u1ed1n nh\u00e2n hai s\u1ed1 nguy\u00ean \u00e2m, ta nh\u00e2n hai gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a ch\u00fang.<\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3:<br\/>(-8) . (-4) = 8 . 4 = 32<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u0111\u00fang l\u00e0: A. 32<\/span><\/span> <br\/>","column":2}]}],"id_ques":1235},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":" T\u00ednh nhanh:<br\/>(-7) . (-5) = ?<\/span>","select":["A. 30","B. -30","C. -35","D. 35"],"hint":"","explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/>Mu\u1ed1n nh\u00e2n hai s\u1ed1 nguy\u00ean \u00e2m, ta nh\u00e2n hai gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a ch\u00fang.<\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3:<br\/>(-7) . (-5) = 7 . 5 = 35<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u0111\u00fang l\u00e0: D. 35<\/span><\/span> <br\/>","column":2}]}],"id_ques":1236},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" (-15) . (-2) ?<\/span> 0","select":[" >"," < "," = "],"hint":"","explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/>B\u01b0\u1edbc 1: T\u00ednh k\u1ebft qu\u1ea3 c\u1ee7a v\u1ebf tr\u00e1i<br\/>B\u01b0\u1edbc 2: So s\u00e1nh k\u1ebft qu\u1ea3 v\u1eeba t\u00ecm \u0111\u01b0\u1ee3c v\u1edbi s\u1ed1 \u0111\u00e3 cho \u1edf v\u1ebf ph\u1ea3i<br\/>L\u01b0u \u00fd:<\/b><br\/>Mu\u1ed1n nh\u00e2n hai s\u1ed1 nguy\u00ean \u00e2m, ta nh\u00e2n hai gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a ch\u00fang<\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3:<br\/> $\\underbrace{(-15) . (-2)}_{30} $ ?<\/span> 0<br\/>M\u00e0 30 > 0<br\/>N\u00ean (-15) . (-2) > 0<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: ><\/span><\/span> <br\/> ","column":3}]}],"id_ques":1237},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":" (-3) . 7 ?<\/span> 0","select":[" >"," < "," = "],"hint":"","explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/>B\u01b0\u1edbc 1: T\u00ednh k\u1ebft qu\u1ea3 c\u1ee7a v\u1ebf tr\u00e1i<br\/>B\u01b0\u1edbc 2: So s\u00e1nh k\u1ebft qu\u1ea3 v\u1eeba t\u00ecm \u0111\u01b0\u1ee3c v\u1edbi s\u1ed1 \u0111\u00e3 cho \u1edf v\u1ebf ph\u1ea3i<br\/>L\u01b0u \u00fd:<\/b><br\/>Mu\u1ed1n nh\u00e2n hai s\u1ed1 nguy\u00ean kh\u00e1c d\u1ea5u, ta nh\u00e2n hai gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a ch\u00fang r\u1ed3i \u0111\u1eb7t d\u1ea5u (-) tr\u01b0\u1edbc k\u1ebft qu\u1ea3 nh\u1eadn \u0111\u01b0\u1ee3c<\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3:<br\/> $\\underbrace{(-3) . 7}_{-21} $ ?<\/span> 0<br\/>M\u00e0 -21 < 0<br\/>N\u00ean (-3) . 7 < 0<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <<\/span><\/span> <br\/> ","column":3}]}],"id_ques":1238},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":" (-18) . (-7) ?<\/span> 126","select":[" >"," < "," = "],"hint":"","explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/>B\u01b0\u1edbc 1: T\u00ednh k\u1ebft qu\u1ea3 c\u1ee7a v\u1ebf tr\u00e1i<br\/>B\u01b0\u1edbc 2: So s\u00e1nh k\u1ebft qu\u1ea3 v\u1eeba t\u00ecm \u0111\u01b0\u1ee3c v\u1edbi s\u1ed1 \u0111\u00e3 cho \u1edf v\u1ebf ph\u1ea3i<br\/>L\u01b0u \u00fd:<\/b><br\/>Mu\u1ed1n nh\u00e2n hai s\u1ed1 nguy\u00ean \u00e2m, ta nh\u00e2n hai gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a ch\u00fang<\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3:<br\/> $\\underbrace{(-18) . (-7)}_{126} $ ?<\/span> 126<br\/>N\u00ean (-18) . (-7) = 126<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: =<\/span><\/span> <br\/> ","column":3}]}],"id_ques":1239},{"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":[[["-20"],["27"]]],"list":[{"point":5,"width":60,"type_input":"","ques":" <table><tr><th>a<\/th><th>5<\/th><th>-3<\/th><\/tr><tr><td>b<\/td><td>-4<\/td><td>-9<\/td><\/tr><tr><td>a . b<\/td><td>_input_<\/td><td>_input_<\/td><\/tr><\/table>","hint":"","explain":"H\u01b0\u1edbng d\u1eabn:<\/span><br\/>+ Mu\u1ed1n nh\u00e2n hai s\u1ed1 nguy\u00ean \u00e2m, ta nh\u00e2n hai gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a ch\u00fang<br\/>+ Mu\u1ed1n nh\u00e2n hai s\u1ed1 nguy\u00ean kh\u00e1c d\u1ea5u, ta nh\u00e2n hai gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a ch\u00fang r\u1ed3i \u0111\u1eb7t d\u1ea5u (-) tr\u01b0\u1edbc k\u1ebft qu\u1ea3 nh\u1eadn \u0111\u01b0\u1ee3c<\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>+ a = 5; b = -4 th\u00ec:<br\/>$\\begin{align*}a . b&= 5 . (-4) \\\\&= -(5 . 4)\\\\&= -20\\end{align*}$<br\/>+ a = -3; b = -9 th\u00ec:<br\/>$\\begin{align*}a . b&= (-3) . (-9) \\\\&= 3 . 9\\\\&= 27\\end{align*}$<br\/>V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u1ea7n l\u01b0\u1ee3t t\u1eeb tr\u00e1i qua ph\u1ea3i l\u00e0: -20; 27<\/span><\/span> <br\/> "}]}],"id_ques":1240},{"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":[[["12"],["-16"]]],"list":[{"point":5,"width":60,"type_input":"","ques":" <table><tr><th>a<\/th><th>-3<\/th><th>-8<\/th><\/tr><tr><td>b<\/td><td>-4<\/td><td>2<\/td><\/tr><tr><td>a . b<\/td><td>_input_<\/td><td>_input_<\/td><\/tr><\/table>","hint":"","explain":"H\u01b0\u1edbng d\u1eabn:<\/span><br\/>+ Mu\u1ed1n nh\u00e2n hai s\u1ed1 nguy\u00ean \u00e2m, ta nh\u00e2n hai gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a ch\u00fang<br\/>+ Mu\u1ed1n nh\u00e2n hai s\u1ed1 nguy\u00ean kh\u00e1c d\u1ea5u, ta nh\u00e2n hai gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a ch\u00fang r\u1ed3i \u0111\u1eb7t d\u1ea5u (-) tr\u01b0\u1edbc k\u1ebft qu\u1ea3 nh\u1eadn \u0111\u01b0\u1ee3c<\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>+ a = -3; b = -4 th\u00ec:<br\/>$\\begin{align*}a . b&= (-3) . (-4) \\\\&= 3 . 4\\\\&= 12\\end{align*}$<br\/>+ a = -8; b = 2 th\u00ec:<br\/>$\\begin{align*}a . b&= (-8) . 2 \\\\&= -(8 . 2)\\\\&= -16\\end{align*}$<br\/>V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u1ea7n l\u01b0\u1ee3t t\u1eeb tr\u00e1i qua ph\u1ea3i l\u00e0: 12; -16<\/span><\/span> <br\/> "}]}],"id_ques":1241},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/daiso/bai26/lv1/img\/2.jpg' \/><\/center> S\u1ed1 \u00e2m x S\u1ed1 \u00e2m = S\u1ed1 d\u01b0\u01a1ng. \u0110\u00fang hay sai?","select":[" A. \u0110\u00fang"," B. Sai "],"hint":"","explain":" B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3:<br\/>S\u1ed1 \u00e2m x S\u1ed1 \u00e2m = S\u1ed1 d\u01b0\u01a1ng<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n: A. \u0110\u00fang<\/span><\/span> <br\/> ","column":2}]}],"id_ques":1242},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" Cho a l\u00e0 m\u1ed9t s\u1ed1 nguy\u00ean d\u01b0\u01a1ng. H\u1ecfi b l\u00e0 s\u1ed1 nguy\u00ean \u00e2m hay nguy\u00ean d\u01b0\u01a1ng n\u1ebfu t\u00edch a . b l\u00e0 s\u1ed1 nguy\u00ean \u00e2m?","select":[" A. S\u1ed1 nguy\u00ean \u00e2m"," B. S\u1ed1 nguy\u00ean d\u01b0\u01a1ng "],"hint":"","explain":" B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3:<br\/> S\u1ed1 \u00e2m x S\u1ed1 d\u01b0\u01a1ng = S\u1ed1 \u00e2m<br\/> M\u00e0 a l\u00e0 s\u1ed1 nguy\u00ean d\u01b0\u01a1ng, a . b l\u00e0 s\u1ed1 nguy\u00ean \u00e2m n\u00ean b l\u00e0 s\u1ed1 nguy\u00ean \u00e2m.<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n: A. S\u1ed1 nguy\u00ean \u00e2m<\/span><\/span> <br\/> ","column":2}]}],"id_ques":1243},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":" (-2) . (-2) . (-2) . (-2) . (-2) . (-2) . (-2) = ?<\/span>","select":["A. $-2^7$","B. $(-2)^7$","C. $7^2$","D. $(-7)^2$"],"hint":"","explain":" B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3:<br\/> (-2) . (-2) . (-2) . (-2) . (-2) . (-2) . (-2) = $(-2)^7$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: B. $(-2)^7$<\/span> <\/span> <br\/>","column":2}]}],"id_ques":1244},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":" T\u00ednh nhanh:<br\/>(-5) . 125 . (-8) . 20 . (-2) = ?<\/span>","select":["A. 200 000","B. -200 000","C. -100 000","D. 100 000"],"hint":"","explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/>Nh\u00f3m c\u00e1c c\u1eb7p c\u00f3 t\u00edch l\u00e0 s\u1ed1 tr\u00f2n ch\u1ee5c, tr\u00f2n tr\u0103m, tr\u00f2n ngh\u00ecn.... \u0111\u1ec3 t\u00ednh nhanh<br\/>L\u01b0u \u00fd:<\/b><br\/>+ Mu\u1ed1n nh\u00e2n hai s\u1ed1 nguy\u00ean \u00e2m, ta nh\u00e2n hai gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a ch\u00fang<br\/>+ Mu\u1ed1n nh\u00e2n hai s\u1ed1 nguy\u00ean kh\u00e1c d\u1ea5u, ta nh\u00e2n hai gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a ch\u00fang r\u1ed3i \u0111\u1eb7t d\u1ea5u (-) tr\u01b0\u1edbc k\u1ebft qu\u1ea3 nh\u1eadn \u0111\u01b0\u1ee3c<\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>$\\begin{align*}&(-5) . 125 . (-8) . 20 . (-2)\\\\&= [125 . (-8)] . [(-5) . 20] . (-2)\\\\&= -(125 . 8) . [-(5 . 20)] . (-2)\\\\&= (-1000) . (-100) . (-2)\\\\&= 100 000 . (-2)\\\\&= -200 000\\end{align*}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: B. -200 000<\/span><\/span> <br\/>","column":2}]}],"id_ques":1245},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":" T\u00ednh nhanh:<br\/>(-2) . 4 . (-5) . (-15) = ?<\/span>","select":["A. -600","B. 600","C. -700","D. 700"],"hint":"","explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/>Nh\u00f3m c\u00e1c c\u1eb7p c\u00f3 t\u00edch l\u00e0 s\u1ed1 tr\u00f2n ch\u1ee5c, tr\u00f2n tr\u0103m, tr\u00f2n ngh\u00ecn.... \u0111\u1ec3 t\u00ednh nhanh<br\/>L\u01b0u \u00fd:<\/b><br\/>+ Mu\u1ed1n nh\u00e2n hai s\u1ed1 nguy\u00ean \u00e2m, ta nh\u00e2n hai gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a ch\u00fang<br\/>+ Mu\u1ed1n nh\u00e2n hai s\u1ed1 nguy\u00ean kh\u00e1c d\u1ea5u, ta nh\u00e2n hai gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a ch\u00fang r\u1ed3i \u0111\u1eb7t d\u1ea5u (-) tr\u01b0\u1edbc k\u1ebft qu\u1ea3 nh\u1eadn \u0111\u01b0\u1ee3c<\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>$\\begin{align*}&(-2) . 4 . (-5) . (-15)\\\\&= [(-2) . (-5)] . [(-15) . 4] \\\\&= (2. 5) . [-(15 . 4)] \\\\&= 10 . (-60)\\\\&= -600\\end{align*}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: A. -600<\/span><\/span> <br\/>","column":2}]}],"id_ques":1246},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":" Gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c: (3 + x) . (x - 2) khi x = -5 l\u00e0:","select":["A. 9","B. -9","C. -14","D. 14"],"hint":"","explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/>Thay gi\u00e1 tr\u1ecb c\u1ee7a x v\u00e0o bi\u1ec3u th\u1ee9c r\u1ed3i th\u1ef1c hi\u1ec7n t\u00ednh.<br\/>L\u01b0u \u00fd:<\/b><br\/>+ Mu\u1ed1n nh\u00e2n hai s\u1ed1 nguy\u00ean \u00e2m, ta nh\u00e2n hai gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a ch\u00fang<br\/>+ Mu\u1ed1n nh\u00e2n hai s\u1ed1 nguy\u00ean kh\u00e1c d\u1ea5u, ta nh\u00e2n hai gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a ch\u00fang r\u1ed3i \u0111\u1eb7t d\u1ea5u (-) tr\u01b0\u1edbc k\u1ebft qu\u1ea3 nh\u1eadn \u0111\u01b0\u1ee3c<\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>Thay x = -5 v\u00e0o bi\u1ec3u th\u1ee9c ta \u0111\u01b0\u1ee3c:<br\/>$\\begin{align*}&[3 + (-5)] . (-5 - 2)\\\\&= (3 - 5) . [- (5 + 2)]\\\\&= [-(5 - 3)] . (-7)\\\\&= (-2) . (-7)\\\\&=2 . 7\\\\& = 14\\end{align*}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: D. 14<\/span><\/span> <br\/>","column":2}]}],"id_ques":1247},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":" Gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c: (x - 1) . (x - 2) khi x = -3 l\u00e0:","select":["A. 9","B. -9","C. 20","D. -20"],"hint":"","explain":" H\u01b0\u1edbng d\u1eabn:<\/span><br\/>Thay gi\u00e1 tr\u1ecb c\u1ee7a x v\u00e0o bi\u1ec3u th\u1ee9c r\u1ed3i th\u1ef1c hi\u1ec7n t\u00ednh.<br\/>L\u01b0u \u00fd:<\/b><br\/>+ Mu\u1ed1n nh\u00e2n hai s\u1ed1 nguy\u00ean \u00e2m, ta nh\u00e2n hai gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a ch\u00fang<br\/>+ Mu\u1ed1n nh\u00e2n hai s\u1ed1 nguy\u00ean kh\u00e1c d\u1ea5u, ta nh\u00e2n hai gi\u00e1 tr\u1ecb tuy\u1ec7t \u0111\u1ed1i c\u1ee7a ch\u00fang r\u1ed3i \u0111\u1eb7t d\u1ea5u (-) tr\u01b0\u1edbc k\u1ebft qu\u1ea3 nh\u1eadn \u0111\u01b0\u1ee3c<\/span> <br\/><br\/>B\u00e0i gi\u1ea3i:<\/span><br\/>Thay x = -3 v\u00e0o bi\u1ec3u th\u1ee9c ta \u0111\u01b0\u1ee3c:<br\/>$\\begin{align*}&(-3 - 1) . (-3 - 2)\\\\&= [-(3 + 1)] . [-(3 + 2)]\\\\&= (-4) . (-5)\\\\&= 4 . 5\\\\&=20\\end{align*}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: C. 20<\/span><\/span> <br\/>","column":2}]}],"id_ques":1248},{"time":24,"part":[{"title":"\u0110i\u1ec1n s\u1ed1 th\u00edch h\u1ee3p v\u00e0o \u00f4 tr\u1ed1ng","title_trans":"","temp":"fill_the_blank","correct":[[["-1"]]],"list":[{"point":5,"width":50,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/daiso/bai26/lv1/img\/2.jpg' \/><\/center> $(-1)^{101}$ = _input_","hint":"","explain":"B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3:<br\/>$(-1)^{101}$ = $\\underbrace{(-1) . (-1) ... (-1)}_{101 s\u1ed1}$ = -1<br\/>V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0: -1<\/span><\/span> <br\/><br\/>Nh\u1eadn x\u00e9t:<\/span><br\/>+ T\u00edch m\u1ed9t s\u1ed1 ch\u1eb5n th\u1eeba s\u1ed1 nguy\u00ean \u00e2m s\u1ebd mang d\u1ea5u (+)<br\/>+ T\u00edch m\u1ed9t s\u1ed1 l\u1ebb th\u1eeba s\u1ed1 nguy\u00ean \u00e2m s\u1ebd mang d\u1ea5u (-)<\/span><\/span>"}]}],"id_ques":1249},{"time":24,"part":[{"title":"Trong c\u00e1c \u0111\u00e1p \u00e1n sau, \u0111\u00e1p \u00e1n n\u00e0o sai?","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":" H\u00e3y ch\u1ecdn c\u00e1ch nh\u1eadn bi\u1ebft d\u1ea5u t\u00edch sai:","select":["(+) . (+) $\\rightarrow$ (+)","(+) . (-) $\\rightarrow$ (-)","(-) . (+) $\\rightarrow$ (-)","(-) . (-) $\\rightarrow$ (-)"],"hint":"","explain":" B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3:<br\/>(+) . (+) $\\rightarrow$ (+)<br\/>(-) . (-) $\\rightarrow$ (+)<br\/>(-) . (+) $\\rightarrow$ (-)<br\/>(+) . (-) $\\rightarrow$ (-)<br\/>V\u1eady \u0111\u00e1p \u00e1n sai l\u00e0: (-) . (-) $\\rightarrow$ (-)<\/span><\/span> <br\/>","column":2}]}],"id_ques":1250}],"lesson":{"save":0,"level":1}}

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