Calculus 2 Question: Infinite Series: Direct Comparison Help!?

I am pretty sure I get where your coming from. I took calc 2 for engineers over summer... and this subject was not one of joy. lol. but, We used M\n\ and N\n\. I asked my teacher the same thing, and when your solving to figure out what is what, it does not matter. As long as you know which one your solving for, and keep everything in line, you should end up with the right answer. That is unless, I am thinking of something different. Just choose the A\n\ and B\n\ that will make it easiest to solve for...