$$\frac{4}{9}x = 1 : 8\frac{7}{8}$$
$$\frac{4}{9}x = 1 : \frac{8 \cdot 8 + 7}{8}$$
$$\frac{4}{9}x = 1 : \frac{64 + 7}{8}$$
$$\frac{4}{9}x = 1 : \frac{71}{8}$$
$$\frac{4}{9}x = \frac{8}{71}$$
$$x = \frac{8}{71} : \frac{4}{9}$$
$$x = \frac{8}{71} \cdot \frac{9}{4}$$
$$x = \frac{2}{71} \cdot \frac{9}{1}$$
$$x = \frac{18}{71}$$
Ответ: $$x = \frac{18}{71}$$