已知xy=2(x+y),求(5x-xy+5y)/(3xy-x-y)的值

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已知xy=2(x+y),求(5x-xy+5y)/(3xy-x-y)的值已知xy=2(x+y),求(5x-xy+5y)/(3xy-x-y)的值已知xy=2(x+y),求(5x-xy+5y)/(3xy-x

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

已知xy=2(x+y),求(5x-xy+5y)/(3xy-x-y)的值
(5x-xy+5y)/(3xy-x-y)=[5(x+y)-xy]/[3xy-(x+y)]
=[5(x+y)-2(x+y)]/[6(x+y)-(x+y)]
=1/2

(5x-xy+5y)/(3xy-x-y)
=[5(x+y)-xy]/[3xy-(x+y)]
将x*y替换
得1/2