22. 21/14 = x/9

Решение:

1. \[ \frac{21}{14} = \frac{x}{9} \]
2. \[ x = \frac{21 \times 9}{14} \]
3. \[ x = \frac{3 \times 9}{2} \]
4. \[ x = \frac{27}{2} \]
5. \[ x = 13,5 \]

Ответ: x = 13,5