若X/1-Y/1=1,求X-XY-Y/3Y-XY-3X的值._数学解答

若X/1-Y/1=1,求X-XY-Y/3Y-XY-3X的值.

人气：421 ℃　时间：2020-05-04 17:22:20

解答

X-XY-Y/3Y-XY-3X
上下同除以xy
=(1/y-1/x-1)/(3/x-3/y-1)
=[-1-(1/x-1/y)]/[3(1/x-1/y)-1]
=(-1-1)/(3-1)
=-1