合并同类项:- 2(x-y)的平方- 3(x-y)+5(y-x)的平方+4(y-x)
问题描述：
合并同类项:- 2(x-y)的平方- 3(x-y)+5(y-x)的平方+4(y-x)
答
- 2(x-y)^2- 3(x-y)+5(y-x)^2+4(y-x)
=-(x-y)(2x-2y+3)+(y-x)(5y-5x+4)
=(y-x)(2x-2y+3)+(y-x)(5y-5x+4)
=(y-x)(2x-2y+3+5y-5x+4)
=(y-x)(3y-3x+7
答
-2(x+y）^2-3（x+y）+5（y-x）^2+4（y-x）
=-2x^2-2y^2-3x-3y+5y^2-5x^2+4y-4x
=(-2-5)x^2+(-2+5)y^2+(-3-4)x+(-3+4)y
-7x^2+3y^2-7x+y
答
- 2(x-y)^2- 3(x-y)+5(y-x)^2+4(y-x)
=-(x-y)(2x-2y+3)+(y-x)(5y-5x+4)
=(y-x)(2x-2y+3)+(y-x)(5y-5x+4)
=(y-x)(2x-2y+3+5y-5x+4)
=(y-x)(3y-3x+7)
答
3(x-y)的平方-7(x-y)