已知1/x+1/y=3,求3x-2xy+3y/x+5xy+y的值

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已知1/x+1/y=3,求3x-2xy+3y/x+5xy+y的值
已知1/x+1/y=3,求3x-2xy+3y/x+5xy+y的值

已知1/x+1/y=3,求3x-2xy+3y/x+5xy+y的值
1/x+1/y=3
(x+y)/xy=3
x+y=3xy
(3x-2xy+3y)/(x+5xy+y)
=[3(x+y)-2xy]/[(x+y)+5xy]
=(3*3xy-2xy)/(3xy+5xy)
=7xy/8xy
=7/8