Answer and Explanation:
The journal entries are shown below:
a.
Feb 1
Allowance for doubtful accounts $7,400
To Account receivable-Oakley Co $1,200
To Account receivable-Brookes Co $6,200
(being written off is recorded)
b)
On June 5
Account receivable-Oakley CO $1,200
To Allowance for doubtful accounts $1,200
(Being amount reinstated is recorded)
On June 5
Cash $1,200
Account receivable-Oakley CO $1,200
(Being the cash received is recorded)