Ответ:

  1. 42 + 18 − 40 = 60 − 40 = 20.
  2. 18 + 26 + 16 = 44 + 16 = 60.
  3. 80 − 34 + 16 = 46 + 16 = 62.
  4. 53 + 37 − 66 = 90 − 66 = 24.
  5. 48 − 37 + 79 = 11 + 79 = 90.
  6. 54 + 17 + 19 = 71 + 19 = 90.
  7. 42 − 26 + 50 = 16 + 50 = 66.
  8. 42 + 48 − 16 = 90 − 16 = 74.