Tính

a) \(\frac{2}{5} + \frac{6}{7} = \frac{{14}}{{35}} + \frac{{30}}{{35}} = \frac{{14 + 30}}{{35}} = \frac{{44}}{{35}}\)

b) \(\frac{7}{4} - \frac{3}{8} = \frac{{56}}{{32}} - \frac{{12}}{{32}} = \frac{{56 - 12}}{{32}} = \frac{{44}}{{32}} = \frac{{11}}{8}\)

c) 5 + \(\frac{2}{7}\) = \(\frac{5}{1} + \frac{2}{7} = \frac{{35}}{7} + \frac{2}{7} = \frac{{37}}{7}\)

d) 3 - \(\frac{4}{3}\) = \(\frac{3}{1} - \frac{4}{3} = \frac{9}{3} - \frac{4}{3} = \frac{5}{3}\)