已知4/X-4/Y=3,则分式(2X+3XY-2Y)/(x-6xy-y)=?
问题描述：
已知4/X-4/Y=3,则分式(2X+3XY-2Y)/(x-6xy-y)=?
答
1/x-1/y=3/4
(x-y)/xy=3/4
x-y=(3/4)xy
(2X+3XY-2Y)/(x-6xy-y)
=[2(x-y)+3xy]/[(x-y)-6xy]
=[(3/2)xy+3xy]/[(3/4)xy-6xy]
=[(9/2)xy]/[-21/4)xy]
=-6/7