计算：(2x+ )( -y)=4x^2-y^2

计算(x-2y)^2-4(2x+y)(y-2x)+4x(y-2) 计算【3(x-y)^2(x+y)^-2/4(x+y)^2(x-y)^-2】^-2 计算（2x-3y)(x+4y)-(3x+y)(x-2y) (x-3y)(y+2x)-(4y-3x)(3x+4y)计算 计算:(-x-2y) * (3x-y) 方程式计算5X-2=Y 4X+3=Y 求X.Y 计算:(x-y)^2*(y-x)^2*(x-y)^6 计算(x+y)(x+y)^2(-x-y)^3 计算(x+2y)(x-2y)-(x+2y)-(x-2y)(2y-x)=? 分解因式计算:x^2(x-y)+(y-x)=?x^3+x^2+1\4x=?(2x+y)^2-(x-2y)^2=? 计算(x^8-x^7y+x^5y^3-x^4y^4+x^3y^5-x^y^7+y^8)(x^2+xy+y^2) 计算:[(2x - 3y)^2 - (x-y)(4x+2y)] / 2y