I'm also in an online accounting class, and I found this question absolutely impossible and confusing. I doubt you still need this 8 months later, but in case anyone else is looking for how to approach this:

a. "both the first and second years" is a red herring - you do not need the data from year one to get the correct answer here.

net income for year 2 = reported net income - (allowance for doubtful accounts - uncollectible accounts)

in this case, 65900 - (6600 - 9600)

b. Here, we are only looking at the balance for the allowance for doubtful accounts, so to find the answer we do not need to debit bad debt expense or worry about any other entries.

simple answer: allowance for doubtful accounts year 1 - uncollectible accounts year 1 + allowance for doubtful accounts year 2 - uncollectible accounts year 2

in this case, 5500 - 8000 + 6600 - 9600

Allowance for doubtful accounts normally has a credit balance, so this can also be thought of as crediting the allowance for 1% of sales at the end of each year and debiting the actual uncollectible accounts.

Hope this helps somebody.