Answer
$-3=\displaystyle \log_{5}\frac{1}{125}$
Work Step by Step
We use the definition of logarithm to rewrite a logarithmic equation as an equivalent exponential equation or the other way around:
$m=\log_{a}x$ is equivalent to $a^{m}=x.$
So, with a=5, m=-3, x=1/125,
$5^{-3}=\displaystyle \frac{1}{125}$ is equivalent to $-3=\displaystyle \log_{5}\frac{1}{125}$
