Answer
$\approx-0.6309$
Work Step by Step
Using $\log_a b=\dfrac{\log b}{\log a}$ or the Change-Of-Base Theorem, the given expression, $
\log_{1/3} 2
,$ evaluates to
\begin{array}{l}\require{cancel}
\dfrac{\log2}{\log \dfrac{1}{3}}
\\\\
\approx-0.6309
.\end{array}