15 : (x + 2) = 5

Решение:

1. \( 15 : (x + 2) = 5 \)
2. \( 15 = 5 \cdot (x + 2) \)
3. \( \frac{15}{5} = x + 2 \)
4. \( 3 = x + 2 \)
5. \( x = 3 - 2 \)
6. \( x = 1 \)

Ответ: 1