Since there are no special paameters mentioned to solve the problem, algebra will be employed.
What we have so far: Total debit = $<span>12,200 Total credit = $</span><span>11,500 Total transactions = </span>Total credit - Total debit<span> Final balance = $</span><span>5,000
To solve: Let us use the working equation: Initial Balance = Final Balance + |Total Transactions| Initial Balance = </span>$5,000 + |$11,500 - $12,200| Initial Balance = $5,000 + |-$700| <--- remember that -$700 is an absolute value which makes it positive. Initial Balance = $5,700 <--- What we are looking for.
Checking: Early May: $5,700 Around May : $5,700 - Total Debit (Assumption) Around May : $5,700 - $12,200 = -$6,500 (Assumption) Around May: -$6,500 + Total Credit (Assumption) Around May: -$6,500 + $11,500 = $5,000 (Assumption) 31st of May: $5,000 <--- Proven
∴The answer is: $5,700, the initial balance at the beginning of May.
The dividing line will have to hit the points (0,2) and (3,0) then you can test the point (0,0) which satisfies the inequality, so you will shade the side that has (0,0) on it, so it's the first picture.