Question

To avoid a service​ fee, your checking account balance must be at least ​$400 at the end of each month. Your current balance is ​$443.98. You use your debit card to spend ​$126.07. What possible amounts can you deposit into your account by the end of the month to avoid paying the service​ fee?

Answer 1

The person needs to deposit at least $82.09 in order to avoid service fee.

Explanation:

Current account balance before debit = $443.98

Amount debit = $126.07

Thus, new balance =
`Account\ balance\ - Debit\ amount = \$443.98-\$126.07=\$317.91`

The minimum balance in the account must be at least $400 to avoid service fee.

Let the person deposit
`\$x` in the account in order to make the balance at least $400 to avoid service fee.

Thus the inequality will be:

`x+317.91\geq400`

Subtracting both sides by 317.91.

`x+317.91-317.91\geq400-317.91`

`x\geq 82.09`

Thus, the person needs to deposit at least $82.09 in order to avoid service fee.