Ответ:

  1. 51 + 39 = 90
  2. 78 − 27 = 51
  3. 16 + 2 = 18
  4. 2 · 8 = 16
  5. 86 − 14 = 72
  6. 29 − 21 = 8
  7. 18 : 2 = 9
  8. 61 + 12 = 73
  9. 35 − 22 = 13
  10. 61 + 30 = 91