4. Упростим выражение \(\left(\frac{m^2}{n^3}\right)^2 : \frac{2m^4}{n^8}\).
$$\left(\frac{m^2}{n^3}\right)^2 : \frac{2m^4}{n^8} = \frac{(m^2)^2}{(n^3)^2} : \frac{2m^4}{n^8} = \frac{m^4}{n^6} : \frac{2m^4}{n^8} = \frac{m^4}{n^6} \cdot \frac{n^8}{2m^4} = \frac{m^4n^8}{2m^4n^6} = \frac{n^{8-6}}{2} = \frac{n^2}{2}$$
Ответ: \(\frac{n^2}{2}\)