Ответ:

  1. 12,5 + 5,9 = 18,4.
  2. 18,74 + 3,30 = 22,04.
  3. 6,6 + 14 = 20,6.
  4. 13,720 + 24,318 = 38,038.
  5. 4,18 + 7,52 = 11,70.
  6. 43,523 + 36,477 = 80.

Ответ: 18,4; 22,04; 20,6; 38,038; 11,70; 80.