Вычислите: а) \(\left(7\frac{1}{8}-6\frac{3}{5}\right):4\frac{1}{5}\); б) \(\left(2\frac{2}{3}+1\frac{5}{6}\right):4\frac{1}{2}\); в) \(\frac{23}{24}-\left(\frac{1}{6}+\frac{1}{4}\right)\); г) \(\frac{11}{15}-\left(\frac{2}{3}-\frac{3}{10}\right)\).

1. а) \(7\frac{1}{8}=\frac{57}{8}\), \(6\frac{3}{5}=\frac{33}{5}\).
   \(\frac{57}{8}-\frac{33}{5}=\frac{285-264}{40}=\frac{21}{40}\).
   \(4\frac{1}{5}=\frac{21}{5}\), поэтому \(\frac{21}{40}:\frac{21}{5}=\frac{21}{40}\cdot\frac{5}{21}=\frac{1}{8}\).
2. б) \(2\frac{2}{3}=\frac{8}{3}\), \(1\frac{5}{6}=\frac{11}{6}\).
   \(\frac{8}{3}+\frac{11}{6}=\frac{16}{6}+\frac{11}{6}=\frac{27}{6}=\frac{9}{2}\).
   \(4\frac{1}{2}=\frac{9}{2}\), следовательно \(\frac{9}{2}:\frac{9}{2}=1\).
3. в) \(\frac{1}{6}+\frac{1}{4}=\frac{2}{12}+\frac{3}{12}=\frac{5}{12}\).
   \(\frac{23}{24}-\frac{5}{12}=\frac{23}{24}-\frac{10}{24}=\frac{13}{24}\).
4. г) \(\frac{2}{3}-\frac{3}{10}=\frac{20}{30}-\frac{9}{30}=\frac{11}{30}\).
   \(\frac{11}{15}-\frac{11}{30}=\frac{22}{30}-\frac{11}{30}=\frac{11}{30}\).

Ответ: а) \(\frac{1}{8}\); б) \(1\); в) \(\frac{13}{24}\); г) \(\frac{11}{30}\).