Решение

a) $$1\frac{2}{5}+3\frac{7}{15} = 1\frac{6}{15}+3\frac{7}{15} = 4\frac{13}{15}$$

б) $$4\frac{3}{14}-1\frac{2}{21} = 4\frac{9}{42}-1\frac{4}{42} = 3\frac{5}{42}$$

в) $$3\frac{5}{6}+2\frac{7}{15}-1\frac{29}{30} = 3\frac{25}{30}+2\frac{14}{30}-1\frac{29}{30} = 5\frac{39}{30}-1\frac{29}{30} = 4\frac{10}{30} = 4\frac{1}{3}$$

Ответ:

a) $$4\frac{13}{15}$$

б) $$3\frac{5}{42}$$

в) $$4\frac{1}{3}$$