Ответ:

  1. 8/15 + 3/10 = 16/30 + 9/30 = 5/6.
  2. 2/3 − 1/15 = 10/15 − 1/15 = 3/5.
  3. 7/30 + 3/20 = 14/60 + 9/60 = 23/60.
  4. 1/9 − 1/18 = 1/18.
  5. 3/4 − 0,5 = 3/4 − 1/2 = 1/4.
  6. 1/4 − 1/8 = 1/8.
  7. 11/30 + 3/4 = 22/60 + 45/60 = 1 7/60.
  8. 5/8 − 5/12 = 15/24 − 10/24 = 5/24.
  9. 11/65 + 2/13 = 11/65 + 10/65 = 21/65.
  10. 0,8 + 2/5 = 0,8 + 0,4 = 1,2.
  11. 1/5 + 17/20 = 4/20 + 17/20 = 1 1/20.
  12. 1/7 − 1/14 = 1/14.
  13. 3/10 + 3/4 = 6/20 + 15/20 = 1 1/20.
  14. 28/57 − 3/19 = 28/57 − 9/57 = 1/3.
  15. 2/25 + 0,02 = 0,08 + 0,02 = 0,1.