As you can see from the solution below, one of the keys to problems like this is to find a way to get x in the denominator. This is because plugging ∞ into the bottom of a fraction leaves you with zero rather than with ∞.
(Click image to enlarge.)
To get this problem into the proper form to solve, you need to recall your log properties: like the fact that exponents can be pulled out front (where they then become coefficients) and the fact that a log that contains multiplication can be rewritten as a sum of two separate logs.
