Answer
$\dfrac{1}{4}$
Work Step by Step
Using rules on integer operations, the expression $
\dfrac{-1}{10}\div\dfrac{-2}{5}
$ simplifies to
\begin{array}{l}\require{cancel}
\dfrac{-1}{10}\cdot\dfrac{5}{-2}
\\\\=
\dfrac{-1}{5\cdot2}\cdot\dfrac{5}{-2}
\\\\=
\dfrac{\cancel{-}1}{\cancel{5}\cdot2}\cdot\dfrac{\cancel{5}}{\cancel{-}2}
\\\\=
\dfrac{1}{4}
.\end{array}
