Question

(a^2-1)+(a+1)
----------------
(a^2-1)-(a-1)

Answer 1

Olá!

$\\ \displaystyle \mathsf{\frac{(a^2 - 1) + (a + 1)}{(a^2 - 1) - (a - 1)} =} \\\\\\ \mathsf{\frac{a^2 - 1 + a + 1}{a^2 - 1 - a + 1} =} \\\\\\ \mathsf{\frac{a^2 + a}{a^2 - a} =} \\\\\\ \mathsf{\frac{a(a + 1)}{a(a - 1)}}$

 Se $\mathsf{a \neq 0}$, então podemos simplificar. Daí,

$\boxed{\mathsf{\frac{a + 1}{a - 1}}}$

é a resposta procurada!