Fractional powers with algebraic terms

Simplify the following, giving your answer with a positive index: $\left(4a^4\right)^{\frac{1}{2}}$(4a4)12​

Express $\sqrt[6]{x}$⁶√x in index form.

Express $\sqrt[3]{x^6}$³√x6 as a power of a power, then simplify.