2. Выполните действия: а) \(\frac{11}{15}+\frac{1}{10}-\frac{1}{15}\); б) \(1\frac{3}{10}+1\frac{5}{12}\); в) \(3\frac{1}{6}-2\frac{2}{7}\); г) \(6\frac{15}{21}+2\frac{8}{14}\).

1. \(\frac{11}{15}+\frac{1}{10}-\frac{1}{15}=\frac{10}{15}+\frac{1}{10}=\frac{2}{3}+\frac{1}{10}=\frac{20}{30}+\frac{3}{30}=\frac{23}{30}\).
2. \(1\frac{3}{10}+1\frac{5}{12}=2+\frac{3}{10}+\frac{5}{12}=2+\frac{18}{60}+\frac{25}{60}=2\frac{43}{60}\).
3. \(3\frac{1}{6}-2\frac{2}{7}=\frac{19}{6}-\frac{16}{7}=\frac{133-96}{42}=\frac{37}{42}\).
4. \(6\frac{15}{21}+2\frac{8}{14}=6\frac{5}{7}+2\frac{4}{7}=8\frac{9}{7}=9\frac{2}{7}\).

Ответ: а) \(\frac{23}{30}\); б) \(2\frac{43}{60}\); в) \(\frac{37}{42}\); г) \(9\frac{2}{7}\).