Answer
$\log{\left(3x^4\right)}$
Work Step by Step
Recall:
(1) $n \cdot \log_a{b} = \log_a{\left(b^n\right)}$
(2) $\log_a{b}+\log_a{c}=\log_a{(bc)}$
(3) $\log_a{b} - \log_a{c}=\log_a{\left(\frac{b}{c}\right)}$
Use rule (1) above to obtain:
\begin{align*}
\log{3}+4\log{x}&=\log{3}+\log{\left(x^4\right)}
\end{align*}
Use rule (2) above to obtain:
\begin{align*}
\log{3}+\log{\left(x^4\right)}&=\log{\left(3\cdot x^4\right)}\\
&=\log{\left(3x^4\right)}
\end{align*}
