\(\begin{array}{l}
\dfrac{{ - 52}}{{ - 71}} = \dfrac{{\left( { - 52} \right).\left( { - 1} \right)}}{{\left( { - 71} \right).\left( { - 1} \right)}} = \dfrac{{52}}{{71}};\\
\dfrac{4}{{ - 17}} = \dfrac{{4.\left( { - 1} \right)}}{{\left( { - 17} \right).\left( { - 1} \right)}} = \dfrac{{ - 4}}{{17}};\\
\dfrac{5}{{ - 29}} = \dfrac{{5.\left( { - 1} \right)}}{{\left( { - 29} \right).\left( { - 1} \right)}} = \dfrac{{ - 5}}{{29}};\\
\dfrac{{31}}{{ - 33}} = \dfrac{{31.\left( { - 1} \right)}}{{\left( { - 33} \right).\left( { - 1} \right)}} = \dfrac{{ - 31}}{{33}}.
\end{array}\)
