化简求值：若1/x-21/y=3,求(2x+3xy-2xy)/(x-2xy-y)的值_数学解答

化简求值：若1/x-21/y=3,求(2x+3xy-2xy)/(x-2xy-y)的值

人气：111 ℃　时间：2020-02-04 01:45:25

解答

1/x-1/y=3
y-x=3xy
(2x+3xy-2xy)/(x-2xy-y)
=(-2*3xy+3xy)/(-3xy-2xy)
=-3xy/(-5xy)
=3/5