Final answer:
Amber's account was overdrawn by $20, and after writing a $20 check and incurring a $10 overdraft fee, her new balance is -$50.
Step-by-step explanation:
Starting with Amber's account balance at - $20 (this means she is overdrawn by $20), she then writes a check for $20.00. This transaction would further negative her account balance by $20, taking it to - $40.
However, her bank charges her an additional overdraft fee of $10.00. To find the new status of Amber's account, we add this fee to her already negative balance: - $40 (from the initial balance and the check) - $10 (overdraft fee) = - $50.
Therefore, Amber's new account balance after writing the check and the bank charging the overdraft fee is - $50.