Ответ:

  1. \(14\frac{9}{13}-1\frac{5}{13}+12\frac{11}{13}=25\frac{15}{13}=26\frac{2}{13}\);
  2. \(7\frac{21}{25}-3\frac{12}{25}-1\frac{7}{25}=2\frac{2}{25}\);
  3. \(17\frac{7}{40}+3\frac{9}{40}-\frac{12}{40}=20\frac{4}{40}=20\frac{1}{10}\);
  4. \(23\frac{13}{40}-13\frac{19}{40}-1\frac{20}{40}=8\frac{14}{40}=8\frac{7}{20}\).

Ответ: а) \(26\frac{2}{13}\); б) \(2\frac{2}{25}\); в) \(20\frac{1}{10}\); г) \(8\frac{7}{20}\).