Question

((x^2+1)(x-1)/(x^2-1) = (x^2+1)/(x+1)
why is the denominator of the answer become (x+1)?

Answer 1

\[(x^2+1)(x-1)/(x^2-1)\]\[(x^2+1)(x-1)/(x-1)(x+1)\]\[(x^2+1)/(x+1)\]

Answer 2

The identity goes:\[a^2-b^2=(a-b)(a+b)\]