已知x+y=5,xy=-1,则(3x-4y+2xy)-(2x-5y+5xy)=_______
已知xy/x+y=1/2,则代数式3x-5xy+3y/-x+3xy-y=
已知x^2-xy=5,xy-y^2=-3求3(x^2-xy)-xy+y^2
已知xy^2=-2,求-xy(x^2y^5-xy^3-y)的值.
已知xy^2=-2 求-xy(x^2y^5-xy^3-y)
已知x+y分之xy=2,那么3x-5xy+3y分之3xy-x-y=
已知xy=2(x+y),求(5x-xy+5y)/(3xy-x-y)的值
已知xy/x+y=3,求代数式2x-5xy+2y/x-3xy+y
已知xy/x+y=2,求代数式3x-5xy+3y/-x+2xy-y的值
已知X+Y=2XY,求4X-5XY+4Y 除以X+XY+Y 的值
已知X+Y分之XY=2,求-X+3XY-Y分之3X+5XY+3Y
已知x-y=2xy,求代数式3x-5xy-3y/x+xy-y的值
已知x-y=4xy,则2x+3xy-2yx-2xy-y