Answer
$\left\{-3, 3\right\}$
Work Step by Step
Divide 3 on both sides of the equation to obtain:
$x^2=9$
Take the square root of both sides to obtain:
$x = \pm \sqrt{9}
\\x=\pm \sqrt{3^2}
\\x=\pm 3$
Thus, the solution set of the given equation is $\left\{-3, 3\right\}$.
