已知x^-XY=60 ,XY-Y^=40,求代数式X^-Y^和2X^-5XY+3Y^的值~

已知x*x-xy=60,xy-y*y=40,问x*x-2xy+y*y的值(要过程） 已知:x-xy=40,xy-y=-20,求代数式x-y和x+y-2xy的值. 已知x^2-xy=60´xy-y^2=40,求代数式x^2-y^2和x^2.-2xy+y^2的值 已知x^2-xy=60´xy-y^2=40,求代数式x^2-y^2和x^2.-2xy+y^2的 已知x^-XY=60 ,XY-Y^=40,求代数式X^-Y^和2X^-5XY+3Y^的值~ 已知x^-XY=60 ,XY-Y^=40,求代数式X^-Y^和2X^-5XY+3Y^的值~ 已知x²-xy=60,xy-y²=40,求代数式x²-y²和x²-2xy+y²的值. |x|/x+y/|y|+xy/|xy|= 已知x+y=1,xy=-2,则x²y+xy²-2xy 已知x-xy=8,xy-y=-9,求x+y-2xy的值 已知xy>0,证明xy+xy/1+x/y+y/x>=4 由已知x+y=-2,xy=3那么2(x+xy)-[(xy-3y)-x]-(-xy)等于多少? 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xy^2=-2xy(x^2y^5-xy^3-y) 已知x+y=12,xy=9,求(x+3xy+y)/(xy+xy)的值 已知x^2-xy=5,xy-y^2=-3求3(x^2-xy)-xy+y^2 已知x^-xy=5,xy-y^=-3,求式子3(x^-xy)-xy+y^的值