Answer:
Sept. 1 DR Supplies $1,100
CR Cash $1,100
Sept 5. DR Retained Earnings $490
CR Cash $490
Sept 7 DR Cash $6,300
CR Unearned Service Revenue $6,300
Sept 16 DR Cash $850
CR Accounts Receivable $850
Sept 22 DR Equipment $3,800
CR Cash $1,500
Notes Payable (3,800 - 1,500) $2,300