已知xy/x-y=1/2 求3x-5xy-3y/y+3xy-x的值!_数学解答

已知xy/x-y=1/2 求3x-5xy-3y/y+3xy-x的值!

人气：486 ℃　时间：2019-10-24 13:36:56

解答

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