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