Effect of adjusting entries on the accounting equation 

Required: 

Each of the following independent events requires a year end adjusting entry. Show how each event and its related adjusting entry affects the accounting equation. Assume a December 31 closing date. The first event is recorded as an example.
a. Paid $4,800 cash in advance on October 1 for a one year insurance policy. 
b. Received an $3,600 cash advance for a contract to provide services in the future. The contract required a one year commitment, starting April 1. 
c. Purchased $1,200 of supplies on account. At year's end, $175 of supplies remained on hand. 
d. Paid $9,600 cash in advance on August 1 for a one year lease on office space.