若x+y分之xy=2,则-x+3xy-y分之3x-xy+3y=多少?

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若x+y分之xy=2,则-x+3xy-y分之3x-xy+3y=多少?
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若x+y分之xy=2,则-x+3xy-y分之3x-xy+3y=多少?
若x+y分之xy=2,则-x+3xy-y分之3x-xy+3y=多少?

若x+y分之xy=2,则-x+3xy-y分之3x-xy+3y=多少?
xy/(x+y)=2
(x+y)/xy=1/2
1/x+1/y=1/2
(3x-xy+3y)/(-x+3xy-y)
=(3/y-1+3/x)/(-1/y+3-1/x)
=[3(1/x+1/y)-1]/[(3-(1/x+1/y)]
=(3/2-1)/(3-1/2)
=(1/2)/(5/2)
=1/5

xy=2*(x+y)
-x+3xy-y=x+y
3x-xy+3y=x+y
等式=1