Answer
$4(x+1)(x-2)$
Work Step by Step
All terms are divisible by $4$, so factor out $4$ to obtain:
$=4(x^2-x-2)$
Factor the trinomial. Look for factors of $-2$ whose sum is $-1$. These factors are $1$ and $-2$.
This means that the trinomial can be factored as $(x+1)(x-2)$.
Thus, the completely factored form of the given polynomial is:
$=4(x+1)(x-2)$