Answer and Explanation: 
The Journal entry is shown below:- 
1. Rent expense Dr, $1,920 ($5,760 × 2 ÷ 6) 
 To Prepaid rent $1,920 
(Being rent expense is recorded) 
2. Unearned revenue Dr, $450 
 To Service revenue $450 
(Being service revenue is recorded) 
3. Salary expense Dr, $600 
 To Salary payable $600 
(Being salary expense is recorded) 
4. Supplies expense Dr, $2,120 ($1,100 + $1,700 - $680) 
 To Supplies $2,120 
(Being supplies expense is recorded)