Answer
The solution set is $\left\{-6, 4\right\}$.
Work Step by Step
Multiply $-1$ to both sides of the equation to obtain:
$x^2+2x-24=0$
Factor the trinomial by looking for the factors of $-24$ whose sum is equal to the coefficient of the middle term ($-2$).
These factors are $-4$ and $6$. This means that the factored form of the trinomial is $(x-4)(x+6)$.
Thus,
$x^2+2x-24=0
\\(x-4)(x+6)=0$
Equate each factor to 0; then simplify to obtain:
$x-4=0 \text{ or } x+6=0
\\x=4 \text{ or } x=-6$
The solution set is $\left\{-6, 4\right\}$.