For his long distance phone service, Deandre pays a $7 monthly fee plus 7 cents per minute. Last month, Deandre's long distance bill was $15.47. For how many minutes was Deandre billed?

Answer: Deandre was billed for 121 minutes.

Step-by-step explanation:

Let x represent the number of minutes for which Deandre was billed in a month.

For his long distance phone service, Deandre pays a $7 monthly fee plus 7 cents per minute. Converting 7 cents to dollars, it becomes

7/100 = $0.07

If he made x minutes of distance call in a month, his total cost would be

0.07x + 7

Last month, Deandre's long distance bill was $15.47. It means that

0.07x + 7 = 15.47

0.07x = 15.47 - 7

0.07x = 8.47

x = 8.47/0.07

x = 121