#### Answer

$\color{blue}{\left\{-6, 6\right\}}$

#### Work Step by Step

RECALL:
$a^2-b^2=(a-b)(a+b)$
Since $36=6^2$, the given equation can be written as:
$x^2-6^2=0$
Factor the binomial using the formula above to obtain:
$(x-6)(x+6)=0$
Use the Zero-Factor Property by equating each factor to zero to obtain:
$x-6=0$ or $x+6=0$
Solve each equation to obtain:
$x-6=0
\\x=0+6
\\x=6$
or
$x+6=0
\\x=0-6
\\x=-6$
Therefore, the solution set is $\color{blue}{\left\{-6, 6\right\}}$.