已知3x-3y=xy则1/x-1/y=要过程,答得好加分.

已知xy/x+y=1/2,则代数式3x-5xy+3y/-x+3xy-y= 已知x+y=3,xy=1,则4x+3xy+4y= 已知1/x=1/y=6,则3x-2xy+3y/3xy+x+y=?已知1/x+1/y=6,则3x-2xy+3y/3xy+x+y=? 已知1/x-1/y=-3,则x+3xy-y/3x-2xy-3y= 已知1/x-1/y=-3,则x+5xy-y/3x-2xy-3y= 已知1/X+1/Y=6,则3X-2XY+3y/3XY+X+Y=多少 已知1/x=3+1/y,则(2x-5xy-2y)/(y+3xy-x)=_______. 已知1/x+1/y=3,则2x-3xy+2y/x+xy+y=谢谢了, 已知1/x-1/y=3,则(5x+xy-5y)/(x-xy-y) =9= 已知2/X-1/Y=3,则(X-2Y-XY)/(5XY+6Y-3X)=? 已知2/x-1/y=3,则(2y-x+4xy)/(3x-6y-5xy)=? 已知1/X-1/Y=3 则(5X+XY-5Y)/(X-XY-Y)=? 已知1/x-1/y=3,则5x+xy-5y/x-xy-y等于 已知1/x-1/y=3,则5x+xy-5y/x-xy-y的值为? 已知1/x-1/y=-3,则5x+xy-5y/x-xy-y的值为 已知1/x=1/y+3,则(5x+xy-5y)/(x-xy-y)的值为（ ） 已知1/x-1/y=3,则5x+xy-5y/x-xy-y的值是? 已知x分之1-y分之1=3则x-xy-y分之5x+xy-5y