Đáp án:
$\begin{array}{l}
Bài2\\
1,\dfrac{{ - 3}}{{16}} = \dfrac{{ - 9}}{{48}};\dfrac{5}{{24}} = \dfrac{{10}}{{48}};\dfrac{{ - 21}}{{56}} = \dfrac{{ - 3}}{8} = \dfrac{{ - 18}}{{48}}\\
2,\dfrac{7}{{30}} = \dfrac{{28}}{{120}};\dfrac{{13}}{{60}} = \dfrac{{26}}{{120}};\dfrac{{ - 9}}{{40}} = \dfrac{{ - 27}}{{120}}\\
3,\dfrac{{17}}{{60}} = \dfrac{{51}}{{180}};\dfrac{{ - 5}}{{18}} = \dfrac{{ - 50}}{{180}};\dfrac{{ - 64}}{{90}} = \dfrac{{ - 32}}{{45}} = \dfrac{{ - 128}}{{180}}\\
4,\dfrac{{11}}{{18}} = \dfrac{{22}}{{36}};\dfrac{{ - 5}}{9} = \dfrac{{ - 20}}{{36}};\dfrac{{ - 7}}{{12}} = \dfrac{{ - 21}}{{36}}\\
5,\dfrac{{31}}{{48}};\dfrac{5}{{16}} = \dfrac{{15}}{{48}};\dfrac{{ - 11}}{{16}} = \dfrac{{ - 33}}{{48}}\\
6,\dfrac{7}{{ - 25}} = \dfrac{{ - 21}}{{75}};\dfrac{{ - 4}}{{15}} = \dfrac{{ - 20}}{{75}};\dfrac{1}{3} = \dfrac{{25}}{{75}}
\end{array}$
