Become accustomed to a quick transformation, not this specific one, but all like it.
\(\displaystyle log_{a^n}(x) = \frac{log(x)}{log(a^{n})} = \frac{log(x)}{n\cdot log(a)} = \frac{1}{n}\cdot log_{a}(x)\)
You tell me what this has to do with your homework assignment.