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

2.209

а) \(1-\frac{17}{18}=\frac{1}{18}\); \(\frac{1}{6}-\frac{1}{18}=\frac{3}{18}-\frac{1}{18}=\frac{2}{18}=\frac{1}{9}\)

б) \(\frac{11}{14}-\frac{13}{21}=\frac{33}{42}-\frac{26}{42}=\frac{7}{42}=\frac{1}{6}\); \(3-\frac{1}{6}=2\frac{5}{6}\)

в) \(3\frac{8}{15}+1\frac{9}{10}=3\frac{16}{30}+1\frac{27}{30}=4\frac{43}{30}=5\frac{13}{30}\); \(7\frac{14}{25}-5\frac{13}{30}=7\frac{84}{150}-5\frac{65}{150}=2\frac{19}{150}\)

г) Общий знаменатель 48: \(6\frac{3}{16}=\frac{297}{48}\), \(2\frac{5}{24}=\frac{106}{48}\), \(3\frac{11}{12}=\frac{188}{48}\); \(\frac{297-106-188}{48}=\frac{3}{48}=\frac{1}{16}\)

Ответ: а) \(\frac{1}{9}\); б) \(2\frac{5}{6}\); в) \(2\frac{19}{150}\); г) \(\frac{1}{16}\).