1. Вычислите: а) \(\frac{1}{3}+\frac{2}{9}\); б) \(\frac{23}{30}-\frac{11}{20}\); в) \(\frac{5}{8}\cdot\frac{7}{5}\); г) \(\frac{4}{25}:\frac{8}{5}\); д) \(3\frac{3}{5}+2\frac{1}{3}\); е) \(6\frac{1}{2}-4\frac{2}{3}\); ж) \(3\frac{3}{8}\cdot4\); з) \(5\frac{3}{7}:19\).

а) \(\frac{1}{3}+\frac{2}{9}=\frac{3}{9}+\frac{2}{9}=\frac{5}{9}\).

б) \(\frac{23}{30}-\frac{11}{20}=\frac{46}{60}-\frac{33}{60}=\frac{13}{60}\).

в) \(\frac{5}{8}\cdot\frac{7}{5}=\frac{7}{8}\).

г) \(\frac{4}{25}:\frac{8}{5}=\frac{4}{25}\cdot\frac{5}{8}=\frac{1}{10}\).

д) \(3\frac{3}{5}+2\frac{1}{3}=5+\frac{9}{15}+\frac{5}{15}=5\frac{14}{15}\).

е) \(6\frac{1}{2}-4\frac{2}{3}=\frac{13}{2}-\frac{14}{3}=\frac{39-28}{6}=\frac{11}{6}=1\frac{5}{6}\).

ж) \(3\frac{3}{8}\cdot4=\frac{27}{8}\cdot4=\frac{27}{2}=13\frac{1}{2}\).

з) \(5\frac{3}{7}:19=\frac{38}{7}:19=\frac{38}{7}\cdot\frac{1}{19}=\frac{2}{7}\).

Ответ: а) \(\frac{5}{9}\); б) \(\frac{13}{60}\); в) \(\frac{7}{8}\); г) \(\frac{1}{10}\); д) \(5\frac{14}{15}\); е) \(1\frac{5}{6}\); ж) \(13\frac{1}{2}\); з) \(\frac{2}{7}\).