Answer
$x=10$
Work Step by Step
If $b\gt0$ and $b\ne1$, then $y=log_{b}x$ means $x=b^{y}$ for every $x\gt0$ and every real number $y$.
Therefore, $log_{x}100=2$ is equivalent to $x^{2}=100$.
Now, take the square root of both sides of $x^{2}=100$.
$\sqrt (x^{2})=\sqrt 100$
$x=10$
