-2x^3y^3+6x^2y^2-20xy
(x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y)
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)
x^2-xy-6y^2+3xy+y+2
(x+y)(x-y)-(2xy+3y)平方
已知xy=-2,x-y=3,求(x+y)(x-y)-y^2+(x-y)^2-(6x^2y-2xy^2)÷2y
[x(x^2y^2-xy)-y(x^2-x^3y)]/3x^2y
化简分式方程:x*x-xy-y*y/x*x-3x-6y+2xy
x^8-x^7y+x^6y^2-x^5y^3+x^4y^4-x^3y^5+x^2y^-xy^7+y^8
已知xy/x+y=6,求3x-2xy+3y/-x+3xy-y的值.
已知xy=-2,x-y=3,求(x+y)(x-y)-y²+(x-y)²-(6x²y-2xy
已知:x/y=-2,求x^2-2xy-3y^2/x^-6xy