Ответ:

  1. 7 + 6 = 13
  2. 6 + 7 = 13
  3. 5 + 8 = 13
  4. 80 + 0 + 3 = 83
  5. 70 − 0 + 9 = 79
  6. 0 + 90 + 5 = 95
  7. 18 − 9 = 9
  8. 17 − 9 = 8
  9. 17 − 8 = 9