Answer
The solution set is $\left\{-2, 2\right\}$.
Work Step by Step
Add $-4$ to both sides to obtain:
$0=n^2-4$
RECALL:
A difference of two square can be factored using the formula:
$a^2-b^2=(a-b)(a+b)$
Factor the difference of two squares to obtain:
$0=(n-2)(n+2)$
Equate each factor to 0, and then solve each equation to obtain:
$n-2=0 \text{ or } n+2 = 0
\\n=2 \text{ or } n=-2$
The solution set is $\left\{-2, 2\right\}$.
