Answer:
[tex]\frac{2(a+4b)}{a^2 -b^2 }[/tex]
Step-by-step explanation:
[tex]\frac{3}{a-b} -\frac{1}{a+b} +\frac{4b}{(a-b)(a+b)}[/tex] =
[tex]\frac{3(a+b)}{(a-b)(a+b)} -\frac{a-b}{(a-b)(a+b)} +\frac{4b}{(a-b)(a+b)}[/tex] =
[tex]\frac{3a + 3b -a + b + 4b}{(a-b)(a+b)}[/tex] =
[tex]\frac{2(a+4b)}{a^2 -b^2 }[/tex]
