4 1 -- -- = 5 10

$$\frac{4}{5} - \frac{1}{10} = \frac{4 \cdot 2}{5 \cdot 2} - \frac{1}{10} = \frac{8}{10} - \frac{1}{10} = \frac{7}{10}$$

Ответ: $$\frac{7}{10}$$