Answer
$-\dfrac{11}{15}$
Work Step by Step
Using operations on real numbers, the given expression, $
-\dfrac{1}{3}-\dfrac{2}{5}
,$ evaluates to
\begin{array}{l}\require{cancel}
-\dfrac{5}{15}-\dfrac{6}{15}
\\\\=
\dfrac{-5-6}{15}
\\\\=
\dfrac{-11}{15}
\\\\=
-\dfrac{11}{15}
.\end{array}