2.344 Выполните действия: a) $$\frac{9}{52} \cdot 4\frac{1}{3} + (3\frac{2}{3} + 2\frac{4}{5})\cdot \frac{60}{97} + \frac{5}{36} \cdot 4\frac{1}{5}$$; б) $$(\frac{5}{9} + \frac{1}{5})\cdot (28\frac{6}{7}-19\frac{5}{14}) \cdot \frac{9}{17} - \frac{1}{5}$$.

a) $$\frac{9}{52} \cdot 4\frac{1}{3} + (3\frac{2}{3} + 2\frac{4}{5})\cdot \frac{60}{97} + \frac{5}{36} \cdot 4\frac{1}{5} = \frac{9}{52} \cdot \frac{13}{3} + (\frac{11}{3} + \frac{14}{5})\cdot \frac{60}{97} + \frac{5}{36} \cdot \frac{21}{5} = \frac{3}{4} \cdot \frac{1}{1} + (\frac{55}{15} + \frac{42}{15})\cdot \frac{60}{97} + \frac{1}{12} \cdot \frac{7}{1} = \frac{3}{4} + \frac{97}{15} \cdot \frac{60}{97} + \frac{7}{12} = \frac{3}{4} + \frac{4}{1} + \frac{7}{12} = \frac{9}{12} + \frac{48}{12} + \frac{7}{12} = \frac{64}{12} = \frac{16}{3} = 5\frac{1}{3}$$;

б) $$(\frac{5}{9} + \frac{1}{5})\cdot (28\frac{6}{7}-19\frac{5}{14}) \cdot \frac{9}{17} - \frac{1}{5} = (\frac{25}{45} + \frac{9}{45})\cdot (28\frac{12}{14}-19\frac{5}{14}) \cdot \frac{9}{17} - \frac{1}{5} = \frac{34}{45} \cdot 9\frac{7}{14} \cdot \frac{9}{17} - \frac{1}{5} = \frac{34}{45} \cdot \frac{133}{14} \cdot \frac{9}{17} - \frac{1}{5} = \frac{2}{5} \cdot \frac{19}{2} \cdot \frac{1}{1} - \frac{1}{5} = \frac{19}{5} - \frac{1}{5} = \frac{18}{5} = 3\frac{3}{5}$$.

Ответ: a) $$5\frac{1}{3}$$; б) $$3\frac{3}{5}$$.