4X( X+Y)- (2X+Y)(2X-Y)
Những câu hỏi liên quan
a) 4x²(x³-2x+3) b) (4x³y⁴-6x²y³+2x²y²):2x²y²
a: \(=4x^5-8x^3+12x^2\)
b: \(=2xy^2-3y+1\)
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Rút gọn các biểu thức sau:
a) ((1/x^2+4x+4)-(1/x^2-4x+4)):((1/x+2)+(1/x^2-2))
b)((2x/2x-y)-(4x^2/4x^2+4xy+y^2)):((2x/4x^2-y^2)+(1/y-2x))
a,sửa đề : \(\left(\frac{1}{x^2+4x+4}-\frac{1}{x^2-4x+4}\right):\left(\frac{1}{x+2}+\frac{1}{x^2-4}\right)\)
\(=\left(\frac{1}{\left(x+2\right)^2}-\frac{1}{\left(x-2\right)^2}\right):\left(\frac{x-2+1}{\left(x+2\right)\left(x-2\right)}\right)\)
\(=\left(\frac{x^2-4x+4-x^2-4x-4}{\left(x+2\right)^2\left(x-2\right)^2}\right):\left(\frac{x-1}{\left(x+2\right)\left(x-2\right)}\right)\)
\(=\frac{-8x\left(x+2\right)\left(x-2\right)}{\left(x+2\right)^2\left(x-2\right)^2\left(x-1\right)}=\frac{-8x}{\left(x-1\right)\left(x^2-4\right)}\)
b, \(\left(\frac{2x}{2x-y}-\frac{4x^2}{4x^2+4xy+y^2}\right):\left(\frac{2x}{4x^2-y^2}+\frac{1}{y-2x}\right)\)
\(=\left(\frac{2x}{2x-y}-\frac{4x^2}{\left(2x+y\right)^2}\right):\left(\frac{2x}{\left(2x-y\right)\left(2x+y\right)}-\frac{1}{2x-y}\right)\)
\(=\left(\frac{2x\left(2x+y\right)^2-4x^2\left(2x-y\right)}{\left(2x-y\right)\left(2x+y\right)^2}\right):\left(\frac{2x-\left(2x+y\right)}{\left(2x-y\right)\left(2x+y\right)}\right)\)
\(=\left(\frac{8x^3+8x^2y+2xy^2-8x^3+4x^2y}{\left(2x-y\right)\left(2x+y\right)^2}\right):\left(\frac{-y}{\left(2x-y\right)\left(2x+y\right)}\right)\)
\(=-\left(\frac{12x^2y+xy^2}{2x+y}\right)=\frac{-12x^2y-xy^2}{2x+y}\)
38. Chọn câu sai:
A. 16x^2 (x-y) - x + y= (2x-1) (2x+1)(4x^2+1)(x-y)
B. 16x^3 - 54y^5 = 2(2x -3y) (4x^2 + 6xy + 9y^2)
C. 16x^5 - 54y = 2(2x-3y) (2x + 3y)^2
D. 16x^4 (x-y) - x + y = (4x^2 -1 (4x^2 +1) (x-y)
Thực hiện phép tính a, ½x²y . (2x³-x²+4x-1) b,(-2x²y+½xy²-3) . (-2x²y) c,(x+2). (3x²-4x) d, (5x-2y) . (x²-xy+1)
c: \(=3x^3-4x^2+6x^2-8x=3x^2+2x^2-8x\)
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*Cộng các phân thức sau:a) x^2/x+1 + 2x/x^2-1 + 1/1+x+1 b) 2x+y/2x^2-y + 8y/y^2-4x^2+2x-y/2x^2+xy
a) \(\dfrac{x^2}{x+1}+\dfrac{2x}{x^2-1}+\dfrac{1}{1+x+1}\) \(=\dfrac{x^2.\left(x-1\right)\left(x+2\right)}{\left(x+1\right).\left(x-1\right)\left(x+2\right)}+\dfrac{2x.\left(x+2\right)}{\left(x-1\right).\left(x+1\right).\left(x+2\right)}+\dfrac{\left(x-1\right).\left(x+1\right)}{\left(x-1\right)\left(x+1\right).\left(x+2\right)}\)
\(=\dfrac{x^2.\left(x-1\right).\left(x+2\right)+2x.\left(x+2\right)+\left(x-1\right)\left(x+1\right)}{\left(x+1\right).\left(x-1\right).\left(x+2\right)}\)
\(=\dfrac{x^4+x^3-2x^2+2x^2+4x+x^2-1}{\left(x-1\right)\left(x+1\right).\left(x+2\right)}\)
\(=\dfrac{x^4+x^3+x^2+4x-1}{\left(x^2-1\right).\left(x+2\right)}\)
\(=\dfrac{x^4+x^3+x^2+4x-1}{x^3+2x^2-x-2}\)
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Rút gọn
A) ( x+2)(x^2 - 2x + 4)- (18 + x^3)
B) (2x - y)(4x^2 + 2xy + y^2)-(2x+y)(4x^2 - 2xy + y^2)
a,=(x+2).(x^2-2x+2^2)-18-x^3
=x^3 + 2^3 - 18 -x^3=(x^3-x^3)+(8-18) = -10
b, =(2x-y).((2x)2+2xy +y2) - (2x +y).((2x)^2-2xy +y^2)
=(2x)3-y3- (2x)3-y3= -2 .y3
2 ý này áp dụng HĐT : x3+y3=(x+y).(x2-xy+y2)
x3-y3=(x-y).(x2+xy+y2)
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*Cộng các phân thức sau: a) x^2/x+1 + 2x/x^2-1 + 1/1+x+1 b) 2x+y/2x^2-y + 8y/y^2-4x^2+2x-y/2x^2+xy c) 1/x-y +3xy/y^3-x^3 + x-y/x^2+xy+y^2
*Cộng các phân thức sau:
a) x^2/x+1 + 2x/x^2-1 + 1/1+x+1
b) 2x+y/2x^2-y + 8y/y^2-4x^2+2x-y/2x^2+xy
c) 1/x-y +3xy/y^3-x^3 + x-y/x^2+xy+y^2
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Xem chi tiết
a, \(\frac{x^2}{x+1}+\frac{2x}{x^2-1}+\frac{1}{x+1}+1\)
\(=\frac{x^2\left(x-1\right)}{\left(x+1\right)\left(x-1\right)}-\frac{2x}{\left(x-1\right)\left(x+1\right)}+\frac{x-1}{\left(x+1\right)\left(x-1\right)}+\frac{\left(x+1\right)\left(x-1\right)}{\left(x+1\right)\left(x-1\right)}\)
\(=\frac{x^3-x^2-2x+x-1-x^2-1}{\left(x-1\right)\left(x+1\right)}\)
\(=\frac{x^3-2x^2-x-2}{\left(x-1\right)\left(x+1\right)}\)
bai 2 quy tac chuyen ve doi dau
a, 3x ²+6x+9-2x^5: 2x^4+3x:2x
b,4x ²y ²+y ³-2x-y ³+5x-3x ²y ³
c,18x+26x ² -48x ²+1x ³-5x ²-17x-x^4.x ²-4x^6
d,y ²-109y+27y+18y ²-7y ²+52y+9+4y ³-3y ².y ³+15y