a) $$√2 = 2^{\frac{1}{2}}$$
б) $$∛17 = 17^{\frac{1}{3}}$$
в) $$\sqrt[8]{a^{12}} = a^{\frac{12}{8}} = a^{\frac{3}{2}}$$
г) $$\sqrt[4]{6^{-5}} = 6^{-\frac{5}{4}}$$