Решение:
а) $-\frac{3}{5} - \frac{9}{10} = \frac{-6}{10} - \frac{9}{10} = \frac{-6 - 9}{10} = \frac{-15}{10} = -\frac{3}{2} = -1\frac{1}{2};$
б) $-\frac{15}{24} - \frac{3}{8} = \frac{-15}{24} - \frac{9}{24} = \frac{-15 - 9}{24} = \frac{-24}{24} = -1;$
в) $\frac{-2}{3} - \frac{5}{6} = \frac{-4}{6} - \frac{5}{6} = \frac{-4 - 5}{6} = \frac{-9}{6} = -\frac{3}{2} = -1\frac{1}{2};$
г) $-\frac{7}{6} - \frac{5}{24} = \frac{-28}{24} - \frac{5}{24} = \frac{-28 - 5}{24} = \frac{-33}{24} = -\frac{11}{8} = -1\frac{3}{8};$
д) $\frac{2}{5} - \frac{13}{50} = \frac{20}{50} - \frac{13}{50} = \frac{20 - 13}{50} = \frac{7}{50};$
е) $-\frac{50}{160} - \frac{9}{16} = \frac{-5}{16} - \frac{9}{16} = \frac{-5 - 9}{16} = \frac{-14}{16} = -\frac{7}{8}.$
Ответ:
а) $-1\frac{1}{2};$
б) −1;
в) $-1\frac{1}{2}$;
г) $-1\frac{3}{8}$;
д) $\frac{7}{50};$
е) $-\frac{7}{8}.$