-6/8 - 6/8 =

-6/8 - 6/8 = -12/8 = -1 1/2

-6/8-6/8= -12/8 this can be reduced to
-3/2 or- 1 1/2

mary -- do you think that I didn't give the right answer and that bryan couldn't figure this out?

I don't know why you posted a duplicate answer.