Thực hiện các phép tính sau: - 5/9.(3/10 - 2/5)

a \(\frac{{ - \,5}}{9}\,\,.\,\,\left( {\frac{3}{{10}}\, - \,\frac{2}{5}} \right) = \frac{{ - 5}}{9}.\left( {\frac{{ - 1}}{{10}}} \right) = \frac{1}{{18}}\)

b \[\frac{{ - 5}}{{17}}.\frac{{31}}{{33}} + \frac{{ - 5}}{{17}}.\frac{2}{{33}} + 2\frac{5}{{17}}\]

\( = \frac{{ - 5}}{{17}}.\left( {\frac{{31}}{{33}} + \frac{2}{{33}}} \right) + 2\frac{5}{{17}}\)

\( = \frac{{ - 5}}{{17}} + 2\frac{5}{{17}}\)

\( = 2\)