若实数x,y满足1/x-1/y=5,则分式3x-2xy-3y/x+xy-y的值等于?

1/x-1/y=5
即,(y-x)/xy=5
即,x-y=-5xy
(3x-2xy-3y)/(x+xy-y)
=[3(x-y)-2xy]/[(x-y)+xy]
=(-15xy-2xy)/(-5xy+xy)
=(-17xy)/(-4xy)
=17/4
所以,分式3x-2xy-3y/x+xy-y的值等于17/4