Exponent expression conditional statement

Question

If $a≠-1$, then $(a^4 - a^2)÷ (a+1)=$

Any suggestion how can I start working with this problem

Answer 1

It is $$\frac{a^2(a^2-1)}{a+1}=\frac{a^2(a-1)(a+1)}{a+1}=a^2(a-1)$$ for $a\neq -1$