(9x^4y^5+45x^2y^4)÷(-3xy^2)^2
[-(x-y)^2/xy]^-4*(y^2-xy/x)^3*(x^4/y^10)÷(xy-y^2/x)^-5=-y(y-
化简:x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y)
x^3y(-4y)^2+(-7xy)^2*(-xy)-5xy^3*(-3x)^2
x*-2xy+3y*=9 4x*-5xy+6y*=30
先化简,再求值:[-xy/(x-y)^2]^4*(x^2-xy/x)3*x^4/y^10÷(x/xy-y^2)^5
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)
x^8-x^7y+x^6y^2-x^5y^3+x^4y^4-x^3y^5+x^2y^-xy^7+y^8
(2x-y)(2x+y)+(2x-y)(y-4x)+2y(y-3x)+2x^4y^2÷(xy)^2
计算:4xy-(x+y)^2/xy(x+y)(x-y)÷x^2+xy-2y^2/x^2y+2xy^2
因式分解 求过程 x-xy+3y-3x 2x+xy-y-4x+5y-6
已知x,y>0 2x+y+3=xy 求5x+4y最小值
(x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y)