2. Выполните действие: a) $$\frac{3}{8} + \frac{1}{4}$$; б) $$5\frac{5}{6} - 2\frac{2}{9}$$; в) $$4\frac{2}{3} \cdot 2\frac{4}{7}$$; г) $$\frac{7}{10} : \frac{14}{15}$$.

a) $$\frac{3}{8} + \frac{1}{4} = \frac{3}{8} + \frac{2}{8} = \frac{5}{8}$$

б) $$5\frac{5}{6} - 2\frac{2}{9} = 5\frac{15}{18} - 2\frac{4}{18} = 3\frac{11}{18}$$

в) $$4\frac{2}{3} \cdot 2\frac{4}{7} = \frac{14}{3} \cdot \frac{18}{7} = \frac{2}{1} \cdot \frac{6}{1} = 12$$

г) $$\frac{7}{10} : \frac{14}{15} = \frac{7}{10} \cdot \frac{15}{14} = \frac{1}{2} \cdot \frac{3}{2} = \frac{3}{4}$$