Answer:
Laura's debt has increased by $15, as her account balance has gone from -$30 to -$45. This means that she owes $15 more than what she owed before. A negative account balance indicates that Laura owes money to someone or a company, and the increase in the negative balance implies that her debt has become more significant. It is essential for Laura to keep track of her account and try to improve her financial situation to avoid accumulating debt further.