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
问题描述：
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.
答
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+...