若1/x -1/y =3,求(2x+3xy-2y)/(x-y-2xy)
若1/x -1/y =3,求(2x+3xy-2y)/(x-y-2xy)
数学人气:168 ℃时间:2020-04-28 07:22:35
优质解答
1/x -1/y =3
y-x/xy=3
y-x=3xy
x-y=-3xy
所以
(2x+3xy-2y)/(x-y-2xy)
=[2(x-y)+3xy]/(x-y-2xy)
=[2(-3xy)+3xy]/(-3xy-2xy)
=-3xy/-5xy
=3/5
答:(2x+3xy-2y)/(x-y-2xy)值为3/5.
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