Решение:
- $$\left(\frac{1}{6}\right)^2 = \frac{1}{36}$$
- $$\left(\frac{2}{3}\right)^2 = \frac{4}{9}$$
- $$\left(\frac{7}{8}\right)^2 = \frac{49}{64}$$
- $$\left(\frac{5}{4}\right)^2 = \frac{25}{16}$$
Ответ: $$\frac{1}{36}$$, $$\frac{4}{9}$$, $$\frac{49}{64}$$, $$\frac{25}{16}$$.