Answer
If $x=5$, then $x^2+x=30$ because once $5$ is substituted for $x$ in the expression, the expression evaluates to $30$.
Work Step by Step
If $x =5$, then $x^2+x=30$ because when $5$ is substituted for $x$ in the given expression, the expression evaluates to $30$.
$x^2+x = 5^2 + 5 = 25 + 5 = 30$