3x^2+5xy-2y^2+x+9y-4
(x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y)
x*-2xy+3y*=9 4x*-5xy+6y*=30
[-(x-y)^2/xy]^-4*(y^2-xy/x)^3*(x^4/y^10)÷(xy-y^2/x)^-5=-y(y-
x^3y(-4y)^2+(-7xy)^2*(-xy)-5xy^3*(-3x)^2
化简:x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y)
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
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
若x+y=-1,则x^4+5x^3y+x^2y+8x^2y^2+xy^2+5xy^3+y^4=( )
(-3x^y+2xy)-( )=4x^+xy
5xy^2-[3xy^2-(4xy^2-2x^y)]+x^2y-xy^2如何化简