(a) Construct T-accounts and enter the balances shown. (b) Prepare adjusting journal entries for the following and post to the T-accounts. (Omit explanations.) Open additional T-accounts as necessary. (The books are closed yearly on December 31.) (1) Bad debt expense is estimated to be $1,400. (2) Equipment is depreciated based on a 7-year life (no salvage value). (3) Insurance expired during the year $2,550. (4) Interest accrued on notes payable $3,360. (5) Sales salaries and wages earned but not paid $2,400. (6) Advertising paid in advance $700. (7) Office supplies on hand $1,500, charged to Supplies