因式分解:(1)-a²b-2ab²+ab (2)(x-2)²-x+2(3)x(x+y)(x-y)-x(x+y)²(4)-(x+2)²+16(x-1)²(5)-0.25xy³+0.01xy
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因式分解:(1)-a²b-2ab²+ab (2)(x-2)²-x+2(3)x(x+y)(x-y)-x(x+y)²(4)-(x+2)²+16(x-1)²(5)-0.25xy³+0.01xy
因式分解:(1)-a²b-2ab²+ab (2)
(x-2)²-x+2(3)x(x+y)(x-y)-x(x+y)²(4)-(x+2)²+16(x-1)²
(5)-0.25xy³+0.01xy
因式分解:(1)-a²b-2ab²+ab (2)(x-2)²-x+2(3)x(x+y)(x-y)-x(x+y)²(4)-(x+2)²+16(x-1)²(5)-0.25xy³+0.01xy
(1)
-a²b-2ab²+ab
=ab(-a-2b+1)
(2)
(x-2)²-x+2
=(x-2)²-(x-2)
=(x-2)(x-2-1)
=(x-2)(x-3)
(3)
x(x+y)(x-y)-x(x+y)²
=x(x+y)(x-y-(x+y))
=x(x+y)(-2y)
=-2xy(x+y)
(4)
-(x+2)²+16(x-1)²
=[4(x-1)+(x+2)][4(x-1)-(x+2)]
=(5x-2)(3x-6)
(5)
-0.25xy³+0.01xy
=xy(0.01-0.25y^2)
=xy(0.1-0.5y)(0.1+0.5y)
(x-2)²-x+2
=x²-4x+4-x+2
=x²-5x+6
用十字相乘法:
1 -2
×
1 -3
=(x-2)(x-3)
x(x+y)(x-y)-x(x+y)²
=x(x+y)[(x-y)-(x+y)]
=x(x+y)(x-y-x...
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(x-2)²-x+2
=x²-4x+4-x+2
=x²-5x+6
用十字相乘法:
1 -2
×
1 -3
=(x-2)(x-3)
x(x+y)(x-y)-x(x+y)²
=x(x+y)[(x-y)-(x+y)]
=x(x+y)(x-y-x-y)
=x(x+y)(-2y)
=-2xy(x+y)
-(x+2)²+16(x-1)²
=[4(x-1)]²-(x+2)²
=(4x-4)²-(x+2)²
=(4x-4+x+2)(4x-4-x-2)
=(5x-2)(3x-6)
-0.25xy³+0.01xy
=0.01xy-0.25xy³
=xy(0.01-0.25y²)
=xy(0.1-0.5y)(0.1+0.5y)
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