已知1/X-1/Y=2,求代数式2x-3xy-2y - 知识问答

已知1/X-1/Y=2,求代数式2x-3xy-2y/3x+4xy-3y的值.

4个回答

1/x -1/y=2
(y-x)/(xy)=2
y-x=2xy
x-y=-2xy
(2x-3xy-2y)/(3x+4xy-3y)
=[2(x-y)-3xy]/[3(x-y)+4xy]
=[2(-2xy)-3xy]/[3(-2xy)+4xy]
=(-7xy)/(-2xy)
=7/2

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