Answer:
[tex]\displaystyle 8^{\frac{x}{3}}[/tex]
Step-by-step explanation:
The rules of exponents say ...
[tex]\displaystyle\sqrt[a]{b^c}=b^{\frac{c}{a}}[/tex]
Here, you have a=3, b=8, c=x, so the alternate form is ...
[tex]\displaystyle 8^{\frac{x}{3}}[/tex]