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问题: 已知1/X-1/Y=3则代数式(2X-14XY-2Y)/(X-2XY-Y)的值为

已知1/X-1/Y=3则代数式(2X-14XY-2Y)/(X-2XY-Y)的值为[过程]

解答:

已知1/X-1/Y=3则代数式(2X-14XY-2Y)/(X-2XY-Y)的值为

已知:1/x-1/y=3
所以:1/x-1/y=(y-x)/(xy)=3
即:y-x=3xy
代入到代数式中,就有:
(2x-14xy-2y)/(x-2xy-y)=[2(x-y)-14xy]/[(x-y)-2xy]
=(-6xy-14xy)/(-3xy-2xy)
=(-20xy)/(-5xy)
=4