Consider the following situations that require adjustments for D.B. Brass Company at December 31, Year 1:

1. Owed salary expenses totaling $10,500 that will be paid during January of Year 2
2. The supplies account has a balance of $2,400 and a physical count of the supplies revealed that $660 of unused supplies were available for future use
3. On October 1, Year 1, the company had collected an advance payment from a customer for $54,000 for services to be rendered equally over the six-month period beginning on that date.

Required: Record (in good form) the adjusting entry required for each of the situations described above.