Выполните действия: \( \frac{13}{18} + \frac{7}{12} \); \( \frac{5}{7} - \frac{3}{5} \); \( \frac{5}{6} - \frac{3}{8} - \frac{1}{12} \).

\( \frac{13}{18} + \frac{7}{12} = \frac{52}{72} + \frac{42}{72} = \frac{94}{72} = \frac{47}{36} \); \( \frac{5}{7} - \frac{3}{5} = \frac{25}{35} - \frac{21}{35} = \frac{4}{35} \); \( \frac{5}{6} - \frac{3}{8} - \frac{1}{12} = \frac{40}{48} - \frac{18}{48} - \frac{4}{48} = \frac{18}{48} = \frac{3}{8} \).