(-x)^2·x·(-2y)^3+(2xy)^2·(-x)^3y
[x(x^2y^2-xy)-y(x^2-x^3y)]/3x^2y
(x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y)
(x+y)(x-y)-(2xy+3y)平方
1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y)
化简:x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y)
先化简,再求值:3xy²(-x²y+2x³y²)-4xy(-xy²)·
已知x-y=-2/3,求(x·x+y.y)的完全平方-4xy(x·x+y·y)+4x·x·y·y的值
计算;(xy-x²)÷x²-2xy+y²/xy · x-y/x²
计算[xy(x²-3y)+3xy²]·(-2xy)+x³y²(2x-y)
(3xy)平方/(-xy)+(x-2y)平方-(x+2y)(x-2y)=
计算3xy[2xy-x(y-2)+x-1]
计算:3xy[2xy-x(y-2)+x]