计算:x^2-y^2/x^2-9y^2+(x-2y)^2/9y^2-x^2+5y^2-4xy/x^2-9y^2
(x^2+xy/x-y)/(xy/x-y)计算
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)
化简:x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y)
x-y/xy-y^2计算
计算:(x+y/x-y)÷(xy+x^2)
因式分解:x×x-xy-2y×y-x-y
(x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y)
计算4x方-4xy+y方-4x+2y-15 4x方y方-5x方y方-9y方
x^8-x^7y+x^6y^2-x^5y^3+x^4y^4-x^3y^5+x^2y^-xy^7+y^8
计算:(x-y)^2*(y-x)^2*(x-y)^6
计算(x+y)(x+y)^2(-x-y)^3
作乘法:(x+y)(x^2-xy+y^2);(x-y)(x^2+xy+y^2)