How would I be able to continue this root test?

I was originally solving for

\(\sum_{n=1}^{infinity}(((-1)^n-15/n)^n)^2\)

I am being instructed to use the root test so I set up the following:

\(\lim_{n\rightarrow infinity}\)\(((\sqrt[n]{|(-1)^n(1-(15/n)|})^n)^2\)

However I'm not sure if I can cancel out anything here. Any help?

Guest Apr 18, 2017