2.209 Вычислите: а) \(\frac{1}{6}-(1-\frac{17}{18})\); б) \(3-(\frac{11}{14}-\frac{13}{21})\); в) \(7\frac{14}{25}-(3\frac{8}{15}+1\frac{9}{10})\); г) \(6\frac{3}{16}-2\frac{5}{24}-3\frac{11}{12}\).

1. а) В скобках: \(1-\frac{17}{18}=\frac{1}{18}\). Тогда \(\frac{1}{6}-\frac{1}{18}=\frac{1}{9}\).
2. б) \(\frac{11}{14}-\frac{13}{21}=\frac{33}{42}-\frac{26}{42}=\frac{1}{6}\), поэтому \(3-\frac{1}{6}=2\frac{5}{6}\).
3. в) \(3\frac{8}{15}+1\frac{9}{10}=5\frac{1}{30}\), а \(7\frac{14}{25}-5\frac{1}{30}=2\frac{59}{150}\).
4. г) \(6\frac{3}{16}-2\frac{5}{24}-3\frac{11}{12}=\frac{297}{48}-\frac{122}{48}-\frac{188}{48}=-\frac{13}{48}\).

Ответ: а) \(\frac{1}{9}\); б) \(2\frac{5}{6}\); в) \(2\frac{59}{150}\); г) \(-\frac{13}{48}\).