## Intermediate Algebra (6th Edition)

$-3$
Using the property $\log_b b^x=x$ then the expression $\log 10^{-3}$ is equal to \begin{array}{l} \log_{10} 10^{-3} \\= -3(\log_{10} 10) \\= -3(1) \\= -3 .\end{array}