If your Single Member LLC is NOT set up as a S-Corp then it is a disregarded entity and you file it on schedule C in your personal tax return. So you can combine it on the same schedule C. Don't know if you need to keep the books separate. You could have just kept going in the same set of books.
If your SMLLC is a S-Corp then you need to file a separate Business Tax return 112-S for it.
