已知1/x-1/y=3,求 2X+3XY-2Y/X-2XY-Y 的值//!

问题描述:

已知1/x-1/y=3,求 2X+3XY-2Y/X-2XY-Y 的值//!

1/x-1/y=3
(y-x)/xy=3
y-x=3xy
x-y=-3xy
(2X+3XY-2Y)/(X-2XY-Y)
=[2(x-y)+3xy]/[(x-y)-2xy]
=(-6xy+3xy)/(-3xy-2xy)
=(-3xy)/(-5xy)
=3/5