Rút gọn biểu thức:
a, 5.(2x-1)2+4.(x-1).(x+3)-2.(5-3x)2
b, (2a2+2a+1).(2a2-2a+1)-(2a2+1)2
c, (9x-1)2+(1-5x)2+2.(9x-1).(1-5x)
Những câu hỏi liên quan
Rút gọn biểu thức:
a, 5.(2x-1)2+4.(x-1).(x+3)-2.(5-3x)2
b, (2a2+2a+1).(2a2-2a+1)-(2a2+1)2
c, (9x-1)2+(1-5x)2+2.(9x-1).(1-5x)
Rút gọn biểu thức:
a, 5.(2x-1)2+4.(x-1).(x+3)-2.(5-3x)2
b, (2a2+2a+1).(2a2-2a+1)-(2a2+1)2
c, (9x-1)2+(1-5x)2+2.(9x-1).(1-5x)
Rút gọn:
a) A=(4-5x)2-(3+5x)2
b) B=(3x-1)(1+3x)-(3x+1)2
c) C=(2x+5)3-(2x-5)3-(120x2+49)
d) D=(2a-b+2)3-6(2a-b+2)2+12(2a-b+2)-8-(2a-b)3
a) A=(4-5x)2-(3+5x)2=(4-5x-3-5x)(4-5x+3+5x)=(-25x+1)1=-25x+1
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B=(3x-1)(1+3x)-(3x+1)2=9x2-1-(3x+1)2=9x2-1-(9x2+6x+1)=9x2-1-9x2-6x-1=-6x-2=-2(3x+1)
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Bài 1: rút gọn
a, (2x-1)^2 +4(x-1) (x+3)-2(5-3x)^2
b, (2a^2+2a+1)(2a^2-2a+1)-(2a^2+1)^2
c, (9x-1)^2+(1-5x)^2+2(9x-1)(1-5x)
d, (x^2+5x-1)^2+2(5x-1)(x^2-5x+1)+(5x-1)^2
e, x(x-1)(x+1)-(x+1)(x^2-x+1)
f, x(x+4)(x-4)-(x^2+1)(x^2-1)
Bài 1:
a) Ta có: \(\left(2x-1\right)^2+4\left(x-1\right)\left(x+3\right)-2\left(5-3x\right)^2\)
\(=4x^2-4x+1+4\left(x^2+2x-3\right)-2\left(25-30x+9x^2\right)\)
\(=4x^2-4x+1+4x^2+8x-12-50+60x-18x^2\)
\(=-10x^2+64x-61\)
b) Ta có: \(\left(2a^2+2a+1\right)\left(2a^2-2a+1\right)-\left(2a^2+1\right)^2\)
\(=\left(2a^2+1\right)^2-\left(2a\right)^2-\left(2a^2+1\right)^2\)
\(=-4a^2\)
c) Ta có: \(\left(9x-1\right)^2+\left(1-5x\right)^2+2\left(9x-1\right)\left(1-5x\right)\)
\(=\left(9x-1+1-5x\right)^2\)
\(=\left(4x\right)^2=16x^2\)
d)
Sửa đề: \(\left(x^2+5x-1\right)^2+2\left(5x-1\right)\left(x^2+5x-1\right)+\left(5x-1\right)^2\)
Ta có: \(\left(x^2+5x-1\right)^2+2\left(5x-1\right)\left(x^2+5x-1\right)+\left(5x-1\right)^2\)
\(=\left(x^2+5x-1+5x-1\right)^2\)
\(=\left(x^2+10x-2\right)^2\)
\(=x^4+100x^2+4+20x^3-40x-4x^2\)
\(=x^4+20x^3+96x^2-40x+4\)
e) Ta có: \(x\left(x-1\right)\left(x+1\right)-\left(x+1\right)\left(x^2-x+1\right)\)
\(=x\left(x^2-1\right)-\left(x^3+1\right)\)
\(=x^3-x-x^3-1\)
=-x-1
f) Ta có: \(x\left(x+4\right)\left(x-4\right)-\left(x^2+1\right)\left(x^2-1\right)\)
\(=x\left(x^2-16\right)-\left(x^4-1\right)\)
\(=x^3-16x-x^4+1\)
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Bài 1: Tính a) (2x – 3).(x + 2) – x.(x + 1) b) 5.(x2 – y2) – (x – y).(x + y) c) 2.(1 – x2) + (3x + 1).(x - 2) d) 4x.(x + y) – (2x - y)2 e) 2a(a+1)-(2a2-1) f) 4(x+2)2+(3+2x)(3-2x) g) (x3 - 3x2 + x - 3):( x - 3) h) (2x4 - 5x2 + x3 – 3 - 3x):(x2 - 3)
Đọc tiếp
Bài 1: Tính
a) (2x – 3).(x + 2) – x.(x + 1) b) 5.(x2 – y2) – (x – y).(x + y)
c) 2.(1 – x2) + (3x + 1).(x - 2) d) 4x.(x + y) – (2x - y)2
e) 2a(a+1)-(2a2-1) f) 4(x+2)2+(3+2x)(3-2x)
g) (x3 - 3x2 + x - 3):( x - 3) h) (2x4 - 5x2 + x3 – 3 - 3x):(x2 - 3)
\(a,=2x^2+x-6-x^2-x=x^2-6\\ b,=5x^2-5y^2-x^2+y^2=4x^2-4y^2\\ c,=2-2x^2+3x^2-6x+x-2=x^2-5x\\ d,=4x^2+4xy-4x^2+4xy-y^2=8xy-y^2\\ e,=2a^2+2a-2a^2+1=2a+1\\ f,=4x^2+16x+16+9-4x^2=16x+25\\ g,=\left[x^2\left(x-3\right)+\left(x-3\right)\right]:\left(x-3\right)=x^2+1\\ h,=\left(2x^4-6x^2+x^3-3x+x^2-3\right):\left(x^2-3\right)\\ =\left[2x^2\left(x^2-3\right)+x\left(x^2-3\right)+\left(x^2-3\right)\right]:\left(x^2-3\right)\\ =2x^2+x+1\)
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Rút gọn biểu thức:
a) ( x -5 )2 + ( 2x -1)2 - 3( x-1).(x+1)
b) ( 2a2 + 2a + 1) . ( 2a2 - 2a+1) - ( 2a2 + 1)2
c) ( 9x - 1)2 + ( 1-5x)2 + 2( 9x-1) . ( 1-5x)
Question Expandand simplify: 1. 8(x+5)-3(2x+7)
2. a(2b+c)+b(3c-2a)
3. 2y(y+5x)+x(3x+4y)
answer , 1. 8(x+5)-3(2x+7)=8x+40-6x+21=2x+61
2. a(2b+c)+b(3c-2a)=2ab+ac+3bc-2ab=ac+3bc=3abc^(2)
3. 2y(y+5x)+x(3x+4y)=2y^(2)+10xy+9x^(2)+4xy=9x^(2)+2y^(2)+14xy
a Explain what he has done wrong.
b work out the correct answer
Bài 1: Khai triển hằng đẳng thức:
a, ( x - y + 2z )2
b, ( 2x-3 ). ( 2x+3 ) . ( 4x2+9 )
Bài 2: Rút gọn biểu thức:
a, ( 5x+2 ).( 2-5x ) - ( 3x+2 ).( 2x+5 )2
b, ( -2x-3 )2 + 2(2x+1).( 2x+5 ) + ( 2x+5 )2
Bài 1:
a, \(\left(x-y+2z\right)^2=x^2+y^2+4z^2-2xy-4yz+4zx\)
b, \(\left(2x-3\right)\left(2x+3\right)\left(4x^2+9\right)=\left(4x^2-9\right)\left(4x^2+9\right)=16x^4-81\)
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Xem thêm câu trả lời
1. Rút Gọn
a) -5x (x-3).(2x+4)-(x+3)(x-3)+(5x-2)(3x+4)
b) (4x-1)x(3x+1)-5x^2x(x-3)-(x-4)x(x-5)-7(x^3-2x^2+x-1)
c) (5x-7)(x-9)-(3-x)(2-5x)-2x(x-4)
d)(5x-4)(x+5)-(x+1)(x^2-6)-5x+19
e)(9x^2-5)(x-3)-3x^2(3x+9)-(x-5)(x+4)-9x^3
g) (x-1)^2 - (x+2)^2
Thanks mn nhiều ạ
\(a,-5x\left(x-3\right)\left(2x+4\right)-\left(x+3\right)\left(x-3\right)+\left(5x-2\right)\left(3x+4\right)\)
\(=-5x\left(2x^2-x-12\right)-\left(x^2-9\right)+15x^2+20x-6x-8\)
\(=-10x^3+5x^2+60x-x^2+9+15x^2+20x-6x-8\)
\(=-10x^3+19x^2+74x+1\)
\(b,\left(4x-1\right)x\left(3x+1\right)-5x^2.x\left(x-3\right)-\left(x-4\right)x\left(x-5\right)\)\(-7\left(x^3-2x^2+x-1\right)\)
\(=\left(4x^2-x\right)\left(3x+1\right)-5x^4-15x^3-\left(x^2-4x\right)\left(x-5\right)\)\(-7x^3+14x^2-7x+7\)
\(=12x^3+x^2-x-5x^4-15x^3-x^3+9x^2+20x\)\(-7x^3+14x^2-7x+7\)
\(=-5x^4-11x^3+24x^2+12x+7\)
\(c,\left(5x-7\right)\left(x-9\right)-\left(3-x\right)\left(2-5x\right)-2x\left(x-4\right)\)
\(=5x^2-52x+63-6+17x-5x^2-2x^2+8x\)
\(=-2x^2-27x+57\)
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\(d,\left(5x-4\right)\left(x+5\right)-\left(x+1\right)\left(x^2-6\right)-5x+19\)
\(=5x^2+21x-20-x^3-x^2+6x+6-5x+19\)
\(=-x^3+4x^2+22x+5\)
\(e,\left(9x^2-5\right)\left(x-3\right)-3x^2\left(3x+9\right)-\left(x-5\right)\left(x+4\right)-9x^3\)
\(=9x^3-27x^2-5x+15-9x^3-27x^2-x^2+x+20-9x^3\)
\(=-9x^3-55x^2+4x+35\)
\(g,\left(x-1\right)^2-\left(x+2\right)^2\)
\(=x^2-2x+1-x^2-4x-4\)
\(=-6x-3\)
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