5.301 д) $$4\frac{3}{7} + 15\frac{4}{7} = (4 + 15) + (\frac{3}{7} + \frac{4}{7}) = 19 + \frac{7}{7} = 19 + 1 = 20$$
е) $$3\frac{9}{13} + 4\frac{8}{13} = (3 + 4) + (\frac{9}{13} + \frac{8}{13}) = 7 + \frac{17}{13} = 7 + 1\frac{4}{13} = 8\frac{4}{13}$$
Ответ: 5.301 д) $$20$$; e) $$8\frac{4}{13}$$