Ответ:

  1. \(30-7=23\)
  2. \(37-4=33\)
  3. \(81+9=90\)
  4. \(58+30=88\)
  5. \(80-4=76\)
  6. \(90-3=87\)
  7. \(57-3=54\)
  8. \(29-8=21\)
  9. \(30-8=22\)
  10. \(38+40=78\)
  11. \(30+42=72\)
  12. \(40-7=33\)
  13. \(75-50=25\)
  14. \(84+6=90\)
  15. \(78-7=71\)