Cecil has a credit card that uses the adjusted balance method. for the first 10
days of one of his 30-day billing cycles, his balance was $340. he then made
a purchase for $290, so his balance jumped to $630, and it remained that
amount for the next 10 days. cecil then made a payment of $150, so his
balance for the last 10 days of the billing cycle was $480. if his credit card's
apr is 19%, which of these expressions could be used to calculate the
amount cecil was charged in interest for the billing cycle?