Answer
$x=21$
Work Step by Step
RECALL:
$\log_b{a}=y \longrightarrow b^y=a$
With $a=x+4$, $b=5$, and $y=2$, use the rule above to the given expression to obtain:
$5^2=x+4
\\5(5)=x+4
\\25=x+4$
Subtract $4$ on both sides of the equation to obtain:
$21=x$
