Решение:
а) $-\frac{1}{6} + \frac{1}{9} = \frac{-3}{18} + \frac{2}{18} = \frac{-3 + 2}{18} = -\frac{1}{18};$
б) $\frac{3}{10} - \frac{2}{15} = \frac{9}{30} - \frac{4}{30} = \frac{9 - 4}{30} = \frac{5}{30} = \frac{1}{6};$
в) $-\frac{2}{10} - \frac{6}{15} = \frac{-6}{30} - \frac{12}{30} = \frac{-6 - 12}{30} = \frac{-18}{30} = -\frac{3}{5};$
г) $\frac{3}{8} - \frac{2}{9} = \frac{27}{72} - \frac{16}{72} = \frac{27 - 16}{72} = \frac{11}{72};$
д) $-\frac{5}{12} + \frac{4}{15} = \frac{-25}{60} + \frac{16}{60} = \frac{-25 + 16}{60} = \frac{-9}{60} = -\frac{3}{20};$
е) $\frac{2}{16} - \frac{-3}{39} = \frac{1}{8} - \frac{-1}{13} = \frac{13}{104} - \frac{-8}{104} = \frac{13 + 8}{104} = \frac{21}{104}.$
Ответ:
а) $-\frac{1}{18};$
б) $\frac{1}{6};$
в) $-\frac{3}{5};$
г) $\frac{11}{72};$
д) $-\frac{3}{20};$
е) $\frac{21}{104}.$