Find n such that

$\displaystyle \lim_{x\rightarrow\infty} \frac {((nx+1)^x)}{(nx+1)^x}= 9$

i know the question ends up as e^(-2/n) but can someone show me a different way of solving it other than the fact that

$\displaystyle e^a = \lim_{x\rightarrow\infty} (1+ (a/x))^x$ ?

i attempted to solve it with ln, moving the x's down but it would be great if i could get some assistance

Edit: sorry i couldn't get the language for this math down, any help on the actual problem? XD sorry