Ответ:

  1. \(6+\frac{6}{13}=6\frac{6}{13}\).
  2. \(\frac{6}{57}+4=4\frac{6}{57}=4\frac{2}{19}\).
  3. \(6\frac{4}{9}+5\frac{2}{9}=11\frac{6}{9}=11\frac{2}{3}\).
  4. \(11\frac{8}{11}-8\frac{5}{11}=3\frac{3}{11}\).
  5. \(8\frac{7}{18}+7\frac{5}{18}-4\frac{11}{18}=15\frac{12}{18}-4\frac{11}{18}=11\frac{1}{18}\).
  6. \(18\frac{6}{10}-5\frac{8}{10}+16\frac{1}{10}=34\frac{7}{10}-5\frac{8}{10}=28\frac{9}{10}\).