1.3(x-y)^2+4(x-y)-42.2（2m-n)^2+7（2m-n)-153.x^2-2xy+10x-10y+254.(x-y)^2-2x+2y分组因式分解急.

Question

1.3(x-y)^2+4(x-y)-4 2.2（2m-n)^2 +7（2m-n)-15 3.x^2-2xy+10x-10y+25 4.(x-y)^2-2x+2y
分组因式分解
急.

Answer 1

1. 3(x-y)^2+4(x-y)-4
=[3(x-y)-2]*[(x-y)+2]
=(3x-3y-2)(x-y+2)
.
2. 2（2m-n)^2 +7（2m-n)-15
=[2(2m-n)-3]*[(2m-n)+5]
=(4m-2n-3)(2m-n+5)
.
3. x^2-2xy+10x-10y+25
=x²+10x+25 - 2xy-10y
=(x+5)²-2y(x+5)
=(x+5)(x+5-2y)
=(x+5)(x-2y+5)
.
4. (x-y)^2-2x+2y
=(x-y)²-2(x-y)
=(x-y)(x-y-2)