已知x-y=-3,xy=5,求x^2+y^2的值

已知Y-x=3xy,求(5x+3xy-5y)÷(x-2xy-y) 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分之XY=2,求-X+3XY-Y分之3X+5XY+3Y 已知X-XY-2Y=0求2X+3XY-Y/X-2XY+5Y 已知xy=2(x+y),求(5x-xy+5y)/(3xy-x-y)的值 已知xy=2(x+y),求5x-xy+5y/3xy-x-y的值 已知x-y=3xy,求5x+2xy-5y/x-4xy-y的值 已知xy/x+y=2,求代数式8x-5xy+8y/-x+3xy-y的值 已知xy/x+y=2,求代数式3x-5y+3y/-x+3xy-y 已知xy/(x+y)=2求(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xy^2=-2求xy（2x^3y^7+5x^2y 已知x^2-xy=5,xy-y^2=-3求3(x^2-xy)-xy+y^2 【数学】已知 1/x-1/y=3 求 5x-xy-5y / x-2xy-y=?已知 1/x=1/y 求 2x-3xy-2y / x-2xy-y=? 已知x+y=5,xy=2,求5x+4y-3y-2y+xy的值