2X+Y=3 3X-5Y=11 求XY

已知X+Y分之XY=2,求-X+3XY-Y分之3X+5XY+3Y 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,求代数式3x-5xy-3y/x+xy-y的值 若x+y-5xy=0,求(2x-3xy+2y)/(x+2xy+y)的值 已知xy=2(x+y),求(5x-xy+5y)/(3xy-x-y)的值 已知xy/(x+y)=2求(3x-5y+3y)/(-x+3xy-y) 已知xy/x+y=2,求代数式3x-5y+3y/-x+3xy-y 已知x,y>0 2x+y+3=xy 求5x+4y最小值 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^2-xy=5,xy-y^2=-3求3(x^2-xy)-xy+y^2