Tính.

a) \[\frac{5}{7}\,\, + \,\,2\,\, = \,\,\frac{5}{7}\,\, + \,\,\frac{2}{1}\,\, = \,\,\frac{5}{7}\,\, + \,\,\frac{{14}}{7}\,\, = \,\,\frac{{19}}{7}\]

b) \[5\,\, - \,\,\frac{5}{9}\,\, = \,\,\frac{5}{1}\,\, - \,\,\frac{5}{9}\,\, = \,\,\frac{{45}}{9}\,\, - \,\,\frac{5}{9}\,\, = \,\,\frac{{40}}{9}\]

c) \[3\,\, - \,\,\left( {\frac{2}{5}\,\, - \,\,\frac{1}{3}} \right)\,\, = \,\,\frac{3}{1}\,\, - \,\,\left( {\frac{6}{{15}}\,\, - \,\,\frac{5}{{15}}} \right)\,\, = \,\,\frac{{45}}{{15}}\,\, - \,\,\frac{1}{{15}}\,\, = \,\,\frac{{44}}{{15}}\]

d) \[\frac{1}{2}\,\, - \,\,\frac{1}{5}\,\,:\,\,\frac{3}{5}\,\, = \,\,\frac{1}{2}\,\, - \,\,\frac{1}{5}\,\, \times \,\,\frac{5}{3}\,\, = \,\,\frac{1}{2}\,\, - \,\,\frac{1}{3}\,\, = \,\,\frac{3}{6}\,\, - \,\,\frac{2}{6}\,\, = \,\,\frac{1}{6}\]