Ответ:

  1. 3 4/7 + 4 1/4 = 7 + 16/28 + 7/28 = 7 23/28.
  2. 6 7/8 − 4 5/6 = 6 21/24 − 4 20/24 = 2 1/24.
  3. 9 5/24 − 7 7/16 = 8 53/48 − 7 21/48 = 1 2/3.