Stumped on two problems:

1. $\displaystyle \lim_{n\to\infty}\frac{8^n(2*4^n+3*5^n)}{5^n(2*7^n-3*8^n)}

$

I haven't worked with limits in awhile, and I can't find any examples in my notes involving exponentials.

The second problem is:

2. $\displaystyle \lim_{x\to 4}\frac{\sqrt{1+2x}-3}{\sqrt{x}-2} $

Rationalizing didnt work out very well, my preferred method would have been L Hopitals rule but we havent covered it in class yet so Im not sure if I can use that in my work.

Any help would be greatly appreciated! =)