化简：（2x-y)²-4(x-y)(x+y)

化简：（2x-y)²-4(x-y)(x+y) (2x-y)²-4(x-y)(x+2y) 化简 3(X-Y)²-4(X-Y)+7(X-Y)-6(X-Y)² 化简：{(x+2y)(2y-x)-4y(-x+y) } / (-2x) （x-2y）²+（2x-4y)(x+y)+(x+y)² 化简:(x-3y)(x+y)-(x-2y)(x+2y)-(x-y)平方 x^2-y^2/x+y-4x(x-y)+y^2/2x-y, [(x+2y)^2-(x-2y)^2-(x-2y)(x+2y)-4y^2]/2x 化简 已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y² 化简(x²y-4y²)/(x²+4xy+4y²)*[(4xy)/(x-2y)+x 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 (2x-y)^2-4(x-y)(x+2y)