34. x : 25 = 3/4 : 5

Решение:

1. \[ x : 25 = \frac{3}{4} : 5 \]
2. \[ x = 25 \times \frac{\frac{3}{4}}{5} \]
3. \[ x = 25 \times \frac{3}{4 \times 5} \]
4. \[ x = 25 \times \frac{3}{20} \]
5. \[ x = \frac{75}{20} \]
6. \[ x = \frac{15}{4} \]

Ответ: x = 15/4