4 -:8 7

$$\frac{4}{7} : 8 = \frac{4}{7} : \frac{8}{1} = \frac{4}{7} \cdot \frac{1}{8} = \frac{4 \cdot 1}{7 \cdot 8} = \frac{4}{56} = \frac{1}{14}$$

Ответ: $$\frac{1}{14}$$