Answer
$42$
Work Step by Step
Recall:
(1) $\log_a{x}+\log_a{y}=\log_a{\left(xy\right)}$
(2) $a^{\log_a{b}}=b$
Use rule (1) above to obtain:
\begin{align*}
5^{\log_5{6}+\log_5{7}}&=5^{\log_5{\left(6\cdot7\right)}}\\
&=5^{\log_5{42}}
\end{align*}
Use rule (2) above to obtain:
\begin{align*}
5^{\log_5{\left(42\right)}}&=42
\end{align*}
