[x(x²y²-xy)-y(x²-x³y)]÷3x²y
化简:x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y)
急![(3x+y)²-3(3x-y)(x+y)-(x-3y)(x+3y)]÷(2xy)
[x(x^2y^2-xy)-y(x^2-x^3y)]/3x^2y
x²/xy-x/y
已知xy=-2,x-y=3,求(x+y)(x-y)-y^2+(x-y)^2-(6x^2y-2xy^2)÷2y
(x+y)(x-y)-(2xy+3y)平方
(2x-y)(2x+y)+(2x-y)(y-4x)+2y(y-3x)+2x^4y^2÷(xy)^2
{(x,y) |x|+|y|
x>y?x:y
xy-1+x-y
计算:(x+y/x-y)÷(xy+x^2)
1、(-7x^y)(2x^y-3xy^3+xy) 2、((x-y)^6)/((y-x)^3)/(x-y)