Answer
The solution set is $\left\{-12, 12\right\}$.
Work Step by Step
Add $-144$ to both sides to obtain:
$0=n^2-144
\\0=n^2-12^2$
RECALL:
A difference of two squares can be factored using the formula:
$a^2-b^2=(a-b)(a+b)$
Factor the difference of two squares to obtain:
$0=(n-12)(n+12)$
Equate each factor to 0, and then solve each equation to obtain:
$n-12=0 \text{ or } n+12 = 0
\\n=12 \text{ or } n=-12$
The solution set is $\left\{-12, 12\right\}$.
