My hunch is that the coefficient should belong to one of the middle terms.
Is it right? I'm not sure how to prove it, though.
Expanding this would be a pain. I would write it as , with and . Then you can use a binomial expansion, and when you back-substitute, you'll end up with more binomials you can expand.
Expanding this would be a pain. I would write it as , with and . Then you can use a binomial expansion, and when you back-substitute, you'll end up with more binomials you can expand.
The question only asks for the largest coefficient, not for the expansion.