若1/x-1/y=3,试求(2x-3xy-2y)/(x-2xy-y)的值.

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若1/x-1/y=3,试求(2x-3xy-2y)/(x-2xy-y)的值.

若1/x-1/y=3,试求(2x-3xy-2y)/(x-2xy-y)的值.
若1/x-1/y=3,试求(2x-3xy-2y)/(x-2xy-y)的值.

若1/x-1/y=3,试求(2x-3xy-2y)/(x-2xy-y)的值.
1/x-1/y=3
所以:y-x=3xy
(2x-3xy-2y)/(x-2xy-y)
=【2(x-y)-3xy】/【(x-y)-2xy】
= (-6xy-3xy)/(-3xy-2xy)
= -9xy/(-5xy)
=9/5


(2x-3xy-2y)/(x-2xy-y) : 分式上下同除于xy
=(2/y-3-2/x) / (1/y-2-1/x)
=[-2(1/x - 1/y) - 3] / [-(1/x-1/y) - 2]
=(-6-3) / (-3-2)
=9/5