Ответ:

  1. 24 − (7 + 7) = 24 − 14 = 10.

  2. 40 − (12 + 8) = 40 − 20 = 20.

  3. 50 + 20 − 30 = 70 − 30 = 40.

  4. 70 + (8 + 2) = 70 + 10 = 80.

  5. 20 − 10 + 90 = 10 + 90 = 100.

  6. 15 − 10 + 70 = 5 + 70 = 75.

  7. 14 + 4 − 10 = 18 − 10 = 8.

  8. 15 − (5 + 10) = 15 − 15 = 0.

  9. 75 − 5 + 20 = 70 + 20 = 90.