Answer:
(a) Interest on notes payable of $290 is accrued.
Dr Interest expense 290
Cr Interest payable 290
(b) Services performed but unbilled totals $1,910.
Dr Unbilled revenue 1,910
Cr Service revenue 1,910
(c) Salaries of $900 earned by employees have not been recorded.
Dr Salaries expense 900
Cr Salaries payable 900