化简5(x+y)^2-2(x-y)^3-2(y-x)^3-2(x+y)^2

化简:(x-3y)(x+y)-(x-2y)(x+2y)-(x-y)平方 数学(x-y)^5*(y-x)^3*(x-y)^2 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 化简：[(x+2y)^2-(x+y)(3x-y)-5y^2]/2x (2X-3y)-(5x-y) 【x-3y][x+y]-[x-2y][x +2y]-[x-y [(3x+y)(x-y)-(2x+3y)(x-y)]*(x-y) 有这样一道题:"计算(2*x*x*x-3*x*x*y-2*x*y*y)-(x*x*x-2*x*y*y+y*y*y)+【- 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y [(x+2y)(x-2y)-(2x-y)^2+(3x-y))2x-5y)]/(-x) 计算(x+y)(x+y)^2(-x-y)^3