A.) Deposit $5 a day, so +$5/day $5 (Day 1) + $5 (Day 2) + $5 (Day 3) + $5 (Day 4) + $5 (Day 5) ___________ = $25 for 5 days
After 5 days, you will have $25. So we go back to the -$15 in your bank account. $25 - $15 = $10 Your new total in the bank account is $10 after the $5/day for 5 days has been deposited.
B.) Withdraw $2/day until you have $0. So, we know we have $10 in the bank account $10 - $2 = $8 (Day 1) $8 - $2 = $6 (Day 2) $6 - $2 = $4 (Day 3) $4 - $2 = $2 (Day 4) $2 - $2 = $0 (Day 5) Within 5 days of withdrawing $2 a day, you will have $0 in your bank account.
If your bank account has -$15 in it and you deposit $5 a day, you would have $10.
Since you have $10 after 5 day, and then you withdraw $2 until you have $0, you would be withdrawing $2 for 5 days. What you do is divide 10 by 2 which is 5. Or, you can subtract 2 from 10 until you get 0
