What is $\displaystyle \lim\_{x\to\infty}\left(\frac{17x}{17x+9}\right)^{3x}$?

I tried to solve this problem and could not understand this. 

I know that it is an exponential equation of the type $\infty^{\infty}$. I got to $3x (\ln 17x - \ln (17x+9) = \ln y$. 

How do I proceed from there? Am I doing this incorrectly in the first place?