1. 36+23=? 15+45=? 2. 17+50=? 69-40=? 3. 87-43=? 70-9=? 4. 8+(15-9) = ? 5. (14-7)-4 = ?

Решение:

1. \( 36 + 23 = 59 \)
   \( 15 + 45 = 60 \)
2. \( 17 + 50 = 67 \)
   \( 69 - 40 = 29 \)
3. \( 87 - 43 = 44 \)
   \( 70 - 9 = 61 \)
4. \( 8 + (15 - 9) = 8 + 6 = 14 \)
5. \( (14 - 7) - 4 = 7 - 4 = 3 \)

Ответ: 1. 59; 60. 2. 67; 29. 3. 44; 61. 4. 14. 5. 3.