Evaluate the limit using l'hospitals rule. lim->0 (3^x-6^x)/x. Do not know where to even begin on this one... please help.

If you don't even know where to begin, you must not have read the section on this topic. It says that

the limit of f(x)/g(x) = f'(x)/g'(x)

so, your limit is just

(ln3 * 3^x - ln6 * 6^x)/1
= (ln3-ln6)
= ln(3/6) = -ln2