1.a/a+b + b/a-b 2.3/a²-1 + 2/a+1

1. a/a+b + b/a-b = a(a-b)/a^-b^ + b(a+b)/a^-b^
= a^ - ab +ab +b^ / a^ - b ^
= a^ + b^/a^-b^

2. 3/a^ -1 +2/a+1
= 3/(a+1)(a-1) + 2(a-1)/(a+1)(a-1)
=3+2a-2 / (a+1)(a-1)
=2a+1 /a^-1