1,-8xy÷5x/2y
(1) -3X^-2XY-8XY-(-5Y^2)-2X^2-Y^2
若1/x+1/y=2,则(2x-xy+2y)÷(3x+5xy+3y)
(8xy-3x平方)-5xy-2(3xy-2x平方),其中,x=2,y=-1
若x+y=-1,则x^4+5x^3y+x^2y+8x^2y^2+xy^2+5xy^3+y^4=( )
5x^2y/-1/2xy*3xy^2
1、已知x+y=5,xy=3,求多项式2(x+3y-2xy)-(4x+8y-2xy)的值.
已知xy/x+y=1/2,则代数式3x-5xy+3y/-x+3xy-y=
[-(x-y)^2/xy]^-4*(y^2-xy/x)^3*(x^4/y^10)÷(xy-y^2/x)^-5=-y(y-
计算:(5-xy/x^3-x^2y)/(1-5/xy)^2*(y-x)^3
(x^2-xy)y÷y-x/xy怎么做?
(x+y-2xy)(x+y-2)+(1-xy)²
已知x+y=-1,xy=-2,求代数式-5(x+y)+(x-y)+x(xy+y)的值