Answer
$x\approx 1.0024$
Work Step by Step
Subtract $3$ from each side to obtain:
$$\log{5x}=0.7$$
Recall:
$$\log_a{b}=y \longleftrightarrow a^y=b$$
Use the definition above to obtain:
\begin{align*}
\log{5x}&=0.7\\\\
10^{0.7}&=5x\\\\
\frac{10^{0.7}}{5}&=\frac{5x}{5}\\\\
\frac{10^{0.7}}{5}&=x
\end{align*}
Use a calculator to obtain:
$x\approx 1.0024$