{"segment":[{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":10,"ques":" <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/daiso/bai26/lv3/img\/2.jpg' \/><\/center> 273 . (1 - 354) - 354 . (1 - 273) = <span class='basic_hoi_black'>?<\/span>","select":["A. 81","B. -81","C. -627","D. 627"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1: Th\u1ef1c hi\u1ec7n b\u1ecf ngo\u1eb7c<br\/>B\u01b0\u1edbc 2: Nh\u00f3m c\u00e1c c\u1eb7p t\u00edch c\u00f3 t\u1ed5ng ho\u1eb7c hi\u1ec7u b\u1eb1ng 0 \u0111\u1ec3 th\u1ef1c hi\u1ec7n t\u00ednh nhanh.<\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>$\\begin{align*}&273 . (1 - 354) - 354 . (1 - 273)\\\\&= 273 - 273 . 354 - (354 - 354 . 273)\\\\&= 273 - 354 . 273 - 354 + 354 . 273\\\\&=(273 - 354) + (354 . 273 - 354 . 273)\\\\&=- (354 - 273) + 0\\\\&= -81\\end{align*}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'> B. -81<\/span><\/span> <br\/>","column":2}]}],"id_ques":1271},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":10,"ques":" T\u0129m x, bi\u1ebft:<br\/>18 - 2 (x - 5) = -38","select":["A. x = 23","B. x = -23","C. x = 33","D. x = -33"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1: T\u00ecm 2 (x - 5)<br\/>B\u01b0\u1edbc 2: T\u00ecm x - 5<br\/>B\u01b0\u1edbc 3: T\u00ecm x<\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>$\\begin{align*}18 - 2 (x - 5)&= -38\\\\2 (x - 5)&= 18 - (-38)\\\\2 (x - 5)&= 18 + 38\\\\2(x - 5)&=56\\\\x - 5&= 56 : 2\\\\x - 5&= 28\\\\x&= 28 + 5\\\\x&= 33\\end{align*}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'> C. x = 33<\/span><\/span> <br\/>","column":2}]}],"id_ques":1272},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":10,"ques":" T\u00ecm x, bi\u1ebft:<br\/>(x - 5) . (x - 1) = 0","select":["A. x = -5","B. x = -1","C. x = -1 v\u00e0 x = -5","D. x = 1 ho\u1eb7c x = 5"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>A . B = 0 th\u00ec A = 0 ho\u1eb7c B = 0<\/span> <br\/><span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3:<br\/>(x - 5) . (x - 1) = 0<br\/>$\\Rightarrow$ x - 5 = 0 ho\u1eb7c x - 1 = 0<br\/>+)<br\/> $\\begin{align*}x - 5&=0\\\\x&= 0 + 5\\\\x&= 5\\end{align*}$<br\/>+)<br\/> $\\begin{align*}x - 1&=0\\\\x&= 0 + 1\\\\x&= 1\\end{align*}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'> D. x = 1 ho\u1eb7c x = 5<\/span><\/span> <br\/><\/span>","column":2}]}],"id_ques":1273},{"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":[[["-3"],["5"],["0"]]],"list":[{"point":10,"width":60,"type_input":"","ques":"T\u00ecm c\u00e1c s\u1ed1 x, y, z bi\u1ebft: x + y = 2, y + z = 5, z + x = -3<br\/>x = _input_, y = _input_, z = _input_","hint":"","explain":"<span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3:<br\/>$\\begin{align*}x + y + y + z + z + x&=2 + 5 + (-3)\\\\(x + x) + (y + y) + (z + z)&= 7 - 3\\\\2x + 2y + 2z&= 4\\\\2. (x + y + z)&= 4\\\\x + y + z&= 4 : 2\\\\x + y + z&= 2\\end{align*}$<br\/>+)<br\/> $\\begin{align*}(x + y + z) - (x + y)&=2 - 2\\\\z&= 0 \\end{align*}$<br\/>+)<br\/> $\\begin{align*}(x + y + z) - (y + z)&=2 - 5\\\\x&= - (5 - 2)\\\\x&= -3 \\end{align*}$<br\/>+)<br\/>$\\begin{align*}(x + y + z) - (z + x)&=2 - (-3)\\\\y&= 2 + 3\\\\y&= 5 \\end{align*}$<br\/>V\u1eady c\u00e1c s\u1ed1 c\u1ea7n \u0111i\u1ec1n l\u1ea7n l\u01b0\u1ee3t t\u1eeb tr\u00e1i qua ph\u1ea3i l\u00e0: <span class='basic_pink'> -3; 5; 0<\/span><\/span> <br\/><\/span> "}]}],"id_ques":1274},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":10,"ques":" T\u00ednh gi\u00e1 tr\u1ecb c\u1ee7a bi\u1ec3u th\u1ee9c:<br\/>A = ax + ay + bx + by bi\u1ebft a + b = -2; x + y = 17","select":["A = 32","A = -32","A = 34","A = -34"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/> B\u01b0\u1edbc 1: Thu g\u1ecdn bi\u1ec3u th\u1ee9c A v\u1ec1 d\u1ea1ng xu\u1ea5t hi\u1ec7n a + b, x + y<br\/>B\u01b0\u1edbc 2: Thay a + b, x + y v\u00e0o bi\u1ec3u th\u1ee9c v\u1eeba thu g\u1ecdn \u0111\u1ec3 t\u00ednh.<\/span> <br\/><br\/><span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>$\\begin{align*}A&=ax + ay + bx + by\\\\&= (ax + bx) + (ay + by)\\\\&= (a + b).x + (a + b). y\\\\&= (a + b) . (x + y)\\end{align*}$<br\/>Thay a + b = -2; x + y = 17 v\u00e0o bi\u1ec3u th\u1ee9c A ta \u0111\u01b0\u1ee3c:<br\/>A = (-2) . 17 = -(2 . 17) = -34<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'> A = -34<\/span><\/span> <br\/><\/span>","column":2}]}],"id_ques":1275},{"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":[[["-81"]]],"list":[{"point":10,"width":60,"type_input":"","ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/daiso/bai26/lv3/img\/4.jpg' \/><\/center> $-(-3)^4$ = _input_","hint":"","explain":"<span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/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 class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/> $-(-3)^4$<br\/>= -[(-3) . (-3) . (-3) . (-3)]<br\/>= -(3 . 3 . 3 . 3)<br\/>= -81<br\/>V\u1eady s\u1ed1 c\u1ea7n \u0111i\u1ec1n v\u00e0o \u00f4 tr\u1ed1ng l\u00e0: <span class='basic_pink'> -81<\/span><\/span> <br\/> <\/span> "}]}],"id_ques":1276},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":10,"ques":" Gi\u00e1 tr\u1ecb nh\u1ecf nh\u1ea5t c\u1ee7a bi\u1ec3u th\u1ee9c 5$x^2$ - 1 l\u00e0:","select":["A. 0","B. -3","C. -1","D. -10"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3:<br\/>$x^2$ $\\ge$ 0 v\u1edbi m\u1ecdi x<br\/>$\\Rightarrow $ 5$x^2$ $\\ge$ 0 v\u1edbi m\u1ecdi x<br\/>$\\Rightarrow $ 5$x^2$ - 1$\\ge$ 0 - 1<br\/>$\\Rightarrow $ 5$x^2$ - 1$\\ge$ - 1<br\/>V\u1eady gi\u00e1 tr\u1ecb nh\u1ecf nh\u1ea5t c\u1ee7a bi\u1ec3u th\u1ee9c 5$x^2$ - 1 l\u00e0: <span class='basic_pink'> C. -1<\/span><\/span> <br\/><\/span>","column":2}]}],"id_ques":1277},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":10,"ques":" Gi\u00e1 tr\u1ecb l\u1edbn nh\u1ea5t c\u1ee7a bi\u1ec3u th\u1ee9c 8 - 3 $(x + 1)^2$ l\u00e0:","select":["A. 4","B. 6","C. 8","D. 10"],"hint":"","explain":" <span class='basic_left'><span class='basic_left'><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3:<br\/>$(x + 1)^2$ $\\ge$ 0 v\u1edbi m\u1ecdi x<br\/>$\\Rightarrow$ 3$(x + 1)^2$ $\\ge$ 0 v\u1edbi m\u1ecdi x<br\/>$\\Rightarrow$ -3 $(x + 1)^2$ $\\le$ 0 v\u1edbi m\u1ecdi x<br\/>$\\Rightarrow$ -3 $(x + 1)^2$ + 8 $\\le$ 0 + 8 <br\/>$\\Rightarrow $ -3 $(x + 1)^2$ + 8 $\\ge$ 8<br\/>Hay 8 -3 $(x + 1)^2$ $\\ge$ 8<br\/>V\u1eady gi\u00e1 tr\u1ecb l\u1edbn nh\u1ea5t c\u1ee7a bi\u1ec3u th\u1ee9c 8 - 3$(x + 1)^2$ l\u00e0: <span class='basic_pink'> 8<\/span><br\/>Ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'> C. 8<\/span><\/span> <br\/><\/span><\/span>","column":2}]}],"id_ques":1278},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":10,"ques":" $(-3)^{2000}$ <span class='basic_hoi_black'>?<\/span> $(-2)^{3000}$","select":[" >"," < "," = "],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>\u0110\u01b0a v\u1ec1 d\u1ea1ng l\u0169y th\u1eeba c\u00f9ng c\u01a1 s\u1ed1 ho\u1eb7c c\u00f9ng s\u1ed1 m\u0169 \u0111\u1ec3 so s\u00e1nh.<\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>Ta c\u00f3:<br\/> $\\begin{align*}(-3)^{2000}&= ({(-3)^2})^{1000}\\\\&= 9^{1000}\\end{align*}$<br\/>$\\begin{align*}(-2)^{3000}&= ({(-2)^3})^{1000}\\\\&= (-8)^{1000}\\end{align*}$<br\/>M\u00e0 9 > -8<br\/>N\u00ean $9^{1000}$ > $(-8)^{1000}$<br\/>$\\Rightarrow $ $(-3)^{2000}$ > $(-2)^{3000}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'> ><\/span><\/span> <br\/> ","column":3}]}],"id_ques":1279},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":10,"ques":" <center><img src='https://www.luyenthi123.com/file/luyenthi123/lop6/toan/daiso/bai26/lv3/img\/2.jpg' \/><\/center> (-35) . (-17) - 85 . 17 - 50 . 83 = <span class='basic_hoi_black'>?<\/span>","select":["A. 500","B. -500","C. -5000","D. 5000"],"hint":"","explain":" <span class='basic_left'><span class='basic_green'>H\u01b0\u1edbng d\u1eabn:<\/span><br\/>a.b - a.c = a. (b - c)<\/span> <br\/><br\/><span class='basic_green'>B\u00e0i gi\u1ea3i:<\/span><br\/>$\\begin{align*}&(-35) . (-17) - 85 . 17 - 50 . 83\\\\&= 35 . 17 - 85 . 17 - 50 . 83\\\\&= (35 - 85) . 17 - 50 . 83\\\\&=-50 . 17 - 50 . 83\\\\&=-50 . (17 + 83)\\\\&= -50 . 100\\\\& = -5000\\end{align*}$<br\/>V\u1eady ta ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0: <span class='basic_pink'> C. -5000<\/span><\/span> <br\/>","column":2}]}],"id_ques":1280}],"lesson":{"save":0,"level":3}}