Решение:
- 48 : 6 · 9 = \( 8 \cdot 9 = 72 \)
- 54 : (13 - 4) = \( 54 : 9 = 6 \)
- 72 : (15 - 6) = \( 72 : 9 = 8 \)
- 55 - 40 : 5 · 6 = \( 55 - 8 \cdot 6 = 55 - 48 = 7 \)
- 15 + 3 · (27 - 20) = \( 15 + 3 \cdot 7 = 15 + 21 = 36 \)
- 42 - 7 · (66 - 60) = \( 42 - 7 \cdot 6 = 42 - 42 = 0 \)
Ответ: 72; 6; 8; 7; 36; 0.