Question

Suppose that the credit remaining on a phone card (in dollars) is a linear function of the total calling time (in minutes). When graphed, the function gives a line with a slope of -0.15 . See the figure below. There is $36.60 in credit remaining on the card after 44 minutes of calls. How much credit will there be after 52 minutes of calls?

Answer 1

The credit after 52 minutes of calling time, with a slope of -0.15 representing the rate of decrease per minute, would be $35.40.

Step-by-step explanation:

The question involves a linear function that models the credit remaining on a phone card as a function of the total calling time. Given the credit remaining after 44 minutes is $36.60 and the slope of the function is -0.15, we can calculate the credit after 52 minutes by utilizing the slope which represents the change in credit per minute of calling time.

To find the credit after 52 minutes, we calculate the difference in time, which is 52 minutes - 44 minutes = 8 minutes. Then we multiply this difference by the slope: 8 minutes * (-$0.15/minute).

The decrease in credit is 8 * (-$0.15) = -$1.20. Therefore, the new credit balance is $36.60 - $1.20 = $35.40.