Answer
$x=\left\{ -\dfrac{3}{10},\dfrac{3}{10} \right\}$
Work Step by Step
Dividing both sides by $100,$ the given expression is equivalent to
\begin{array}{l}\require{cancel}
100x^2=9
\\\\
x^2=\dfrac{9}{100}
.\end{array}
Taking the square root of both sides (Square Root Property), the solutions are
\begin{array}{l}\require{cancel}
x=\pm\sqrt{\dfrac{9}{100}}
\\\\
x=\pm\sqrt{\left(\dfrac{3}{10}\right)^2}
\\\\
x=\pm\dfrac{3}{10}
.\end{array}
Hence, the solutions are $
x=\left\{ -\dfrac{3}{10},\dfrac{3}{10} \right\}
.$
