Answer
$10^{3.1}$, $1258.9254$
Work Step by Step
Based on the definition of the common logarithm, we know that $log(x)=log_{10}x$.
Furthermore, recall that $log_{b}x=y$ is equivalent to the statement $b^{y}=x$ (where $x\gt0$, $y$ is a real number, and $b\gt0$ and $b\ne1$).
Therefore, $log(x)=log_{10}x=3.1$ is equivalent to $10^{3.1}=x$.
We know that $x=10^{3.1}\approx1258.9254$.