∵1/x-1/y=2
∴y-x=2xy
∴(3x-2xy-3y)/(x-2xy-y)
=[-3(y-x)-2xy]/[-(y-x)-2xy]
=(-6xy-2xy)/(-2xy-2xy)
=(-8xy)/(-4xy)
=2
1/x-1/y=2,求3x-2xy-3y/x-2xy-y的值
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