试说明x^3y^3-1/2x^2y+y^2-2x^3y^3+0.5x^2y+y^2+x^3y^3-2y^3-3的值与x取

[(3x+y)(x-y)-(2x+3y)(x-y)]*(x-y) 化简:(x-3y)(x+y)-(x-2y)(x+2y)-(x-y)平方 【x-3y][x+y]-[x-2y][x +2y]-[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)+【- 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 计算(x+y)(x+y)^2(-x-y)^3 数学(x-y)^5*(y-x)^3*(x-y)^2 因式分解 (1)6(x-y)^3-3y(y-x)^2 (2)x(x-y)(a-b)-y(y-x)( 已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) (x-y)^2-(x-y)^3因式分解 计算:(-x-2y) * (3x-y)