10) \(\left(-\frac{1}{3}a^5y^3\right)^4=\)

\(\left(-\frac{1}{3}a^5y^3\right)^4=\left(-\frac{1}{3}\right)^4(a^5)^4(y^3)^4=\frac{1}{81}a^{20}y^{12}\).

Ответ: \(\frac{1}{81}a^{20}y^{12}\).