Write in Exponential Form fourth root of (3x)^4

$\sqrt[4]{{(3 x)}^{4}}$

Use $\sqrt[n]{a^{x}} = a^{\frac{x}{n}}$ to rewrite $\sqrt[4]{{(3 x)}^{4}}$ as ${(3 x)}^{\frac{4}{4}}$ .

${(3 x)}^{\frac{4}{4}}$