Answer
$x=4$ and $x=-1$
Work Step by Step
Subtract $8$ from each side:
$$2x^2-6x-8=0$$
Factor out $2$:
$$2(x^2-3x-4)=0$$
Factor the trinomial:
$$2(x-4)(x+1)=0$$
Use the Zero-Product Property by equating each factor with a variable to zero, then solve each equation to obtain:
\begin{align*}
x-4&=0 &\text{or}& &x+1=0\\
x&=4 &\text{or}& &x=-1
\end{align*}
Thus, the solutions are $x=4$ and $x=-1$.
