Answer
$x=892 $
Work Step by Step
Given \begin{equation}
\sqrt{m+8}=30.
\end{equation} The is a radical equation because of the square root term on the left hand side.
\begin{equation}
\begin{aligned}
\sqrt{m+8}& =30\\
\left( \sqrt{m+8} \right)^2& = 30^2 \\
m+8& =900 \\
m& =892.
\end{aligned}
\end{equation} Check. \begin{equation}
\begin{aligned}
\sqrt{892+8}& \stackrel{?}{=}30 \\
30& =30\quad \textbf{True}
\end{aligned}
\end{equation} The solution is $x=892 $.
