2) $$\sqrt{108a^{16}} = \sqrt{36 \cdot 3 \cdot a^{16}} = \sqrt{36} \cdot \sqrt{3} \cdot \sqrt{a^{16}} = 6 \cdot \sqrt{3} \cdot a^8 = 6a^8\sqrt{3}$$
Ответ: $$6a^8\sqrt{3}$$