Question #9daa9

1 Answer
Oct 28, 2016

color(green)(1/(a^2b+1))

Explanation:

If we temporarily replace a^2b with x

(a^2b-1)/(a^4b^2-1) rarr (x-1)/(x^2-1)

We know that x^2-1 can be factored as (x-1)(x+1)

So (x-1)/(x^2-1)= cancel(x-1)/((cancel(x-1))(x+1))=1/(x+1)

Restoring x back to a^2b, we have
color(white)("XXX")(a^2b-1)/(a^4b^2-1)= 1/(a^2b+1)