x^2-3xy=-5.xy+y^2=3.求 x^2-2xy+y^2的值

已知xy^2=-2,求-xy（x^2y^5-xy^3-y)的值. 已知x-xy=8,xy-y=-9,求x+y-2xy的值 若(y-x)/xy=3,求分式(2x+3xy-2y)/(x-2xy-y)的值 已知x-y/xy=3,求分式2x+3xy-2y/x-2xy-y的值. 已知X+Y=3XY,求2X+2Y-XY除以X+Y+2XY的值,要算理. 已知x-y=4xy,求x-2xy-y分之2x+3xy-2y的值! 已知x+y=3xy,求2x+2y-xy/x+y+2xy的值、 若x+y-5xy=0,求(2x-3xy+2y)/(x+2xy+y)的值 已知xy/x+y =3,求2x-3xy+2y/-x+3xy-y 的值. 已知xy/x+y=3,求2x-3xy+2y/-x+3xy-y的值 已知3x=xy+3y,求2x+xy-2y/y-x-xy的值 已知xy/x+y=2,求代数式3x-5xy+3y/-x+2xy-y的值