26. 12,3/60 = 39/7x

Решение:

1. \[ \frac{12,3}{60} = \frac{39}{7x} \]
2. \[ 12,3 \times 7x = 60 \times 39 \]
3. \[ 86,1x = 2340 \]
4. \[ x = \frac{2340}{86,1} \]
5. \[ x \approx 27,1777 \]

Ответ: x \(\approx\) 27,18