Question 172089
Simplify.
a/b-a-b/a+b over a/b-a+b/a-b
---
Comment: Your problem could be more clearly understood if you would use 
parentheses.
----
= [a/(b-a) - b/(a+b)] / [a/(b-a) + b(a-b)]

Rearrange:

= [-a/(a-b) - b/(a+b)] / [-a/(a-b) + b(a-b)]

lcd = (a+b)(a-b)

= [-(a+b)/(a-b)(a+b)] / [-(a-b)/(a-b)]

= [-1/(a-b)] / [-1]

= a-b
===============
Cheers,
Stan H.