已知1/X-1/Y=3,求:3X-2XY-3Y/X-2XY-Y的值_数学解答

已知1/X-1/Y=3,求:3X-2XY-3Y/X-2XY-Y的值

人气：443 ℃　时间：2020-04-20 18:01:59

解答

1/X-1/Y=3
y-x=3xy
x-y=-3xy
3X-2XY-3Y/X-2XY-Y
=[(3x-3y)-2xy]/[(x-y)-2xy]
=(-9xy-2xy)/(-3xy-2xy)
=-11xy/(-5xy)
=11/5