3. Найдите значение выражения: a) $$\frac{1}{4} - (1-\frac{11}{12})$$; б) $$2 - (\frac{13}{33} - \frac{5}{22})$$; в) $$6\frac{3}{16} - (2\frac{3}{8} + 3\frac{5}{12})$$; г) $$8\frac{1}{12} - 3\frac{4}{15} - 1\frac{7}{30}$$; д) $$(13 - 8\frac{5}{12}) + (17\frac{1}{2} - 16\frac{1}{5})$$; e) $$(63\frac{2}{3} + 3\frac{1}{8}) - (13 - 10\frac{5}{9})$$; ж) $$(15\frac{1}{2} - 2\frac{3}{8}) - (5\frac{5}{6} + 6\frac{3}{4}) + (10\frac{2}{3} - 5\frac{5}{8})$$; з) $$(20 - 19\frac{3}{4}) + (17\frac{3}{4} - 17) + (2\frac{1}{2} - \frac{17}{24})$$

a) $$\frac{1}{4} - (1-\frac{11}{12}) = \frac{1}{4} - (\frac{12}{12} - \frac{11}{12}) = \frac{1}{4} - \frac{1}{12} = \frac{3}{12} - \frac{1}{12} = \frac{2}{12} = \frac{1}{6}$$

б) $$2 - (\frac{13}{33} - \frac{5}{22}) = 2 - (\frac{26}{66} - \frac{15}{66}) = 2 - \frac{11}{66} = 2 - \frac{1}{6} = \frac{12}{6} - \frac{1}{6} = \frac{11}{6} = 1\frac{5}{6}$$

в) $$6\frac{3}{16} - (2\frac{3}{8} + 3\frac{5}{12}) = 6\frac{3}{16} - (2\frac{9}{24} + 3\frac{10}{24}) = 6\frac{3}{16} - 5\frac{19}{24} = 6\frac{9}{48} - 5\frac{38}{48} = 5\frac{57}{48} - 5\frac{38}{48} = \frac{19}{48}$$

г) $$8\frac{1}{12} - 3\frac{4}{15} - 1\frac{7}{30} = 8\frac{5}{60} - 3\frac{16}{60} - 1\frac{14}{60} = 7\frac{65}{60} - 3\frac{16}{60} - 1\frac{14}{60} = 4\frac{49}{60} - 1\frac{14}{60} = 3\frac{35}{60} = 3\frac{7}{12}$$

д) $$(13 - 8\frac{5}{12}) + (17\frac{1}{2} - 16\frac{1}{5}) = (12\frac{12}{12} - 8\frac{5}{12}) + (17\frac{5}{10} - 16\frac{2}{10}) = 4\frac{7}{12} + 1\frac{3}{10} = 4\frac{35}{60} + 1\frac{18}{60} = 5\frac{53}{60}$$

e) $$(63\frac{2}{3} + 3\frac{1}{8}) - (13 - 10\frac{5}{9}) = 66\frac{2}{3} + \frac{1}{8} - (13 - 10\frac{5}{9}) = 66\frac{16}{24} + \frac{3}{24} - (2\frac{4}{9}) = 66\frac{19}{24} - 2\frac{4}{9} = 66\frac{57}{72} - 2\frac{32}{72} = 64\frac{25}{72}$$

ж) $$(15\frac{1}{2} - 2\frac{3}{8}) - (5\frac{5}{6} + 6\frac{3}{4}) + (10\frac{2}{3} - 5\frac{5}{8}) = (15\frac{4}{8} - 2\frac{3}{8}) - (5\frac{10}{12} + 6\frac{9}{12}) + (10\frac{16}{24} - 5\frac{15}{24}) = 13\frac{1}{8} - 11\frac{19}{12} + 5\frac{1}{24} = 13\frac{3}{24} - 12\frac{31}{12} + 5\frac{1}{24} = 13\frac{3}{24} - 12\frac{62}{24} + 5\frac{1}{24} = 12\frac{27}{24} - 12\frac{62}{24} + 5\frac{1}{24} = 0 - \frac{35}{24} + 5\frac{1}{24} = 5\frac{1}{24} - 1\frac{11}{24} = 4\frac{25}{24} - 1\frac{11}{24} = 3\frac{14}{24} = 3\frac{7}{12}$$

з) $$(20 - 19\frac{3}{4}) + (17\frac{3}{4} - 17) + (2\frac{1}{2} - \frac{17}{24}) = (19\frac{4}{4} - 19\frac{3}{4}) + \frac{3}{4} + (2\frac{12}{24} - \frac{17}{24}) = \frac{1}{4} + \frac{3}{4} + (1\frac{36}{24} - \frac{17}{24}) = 1 + 1\frac{19}{24} = 2\frac{19}{24}$$