Ответ:

  1. 4 − 1 = 3
  2. 1 + 3 = 4
  3. 2 − 1 = 1
  4. 2 + 3 = 5
  5. 3 − 2 = 1
  6. 2 + 1 = 3
  7. 4 − 2 = 2
  8. 1 + 4 = 5