#### Answer

-1

#### 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, $log(\frac{1}{10})=log_{10}\frac{1}{10}=-1$, because $10^{-1}=\frac{1}{10^{1}}=\frac{1}{10}$.