A monthly service fee to download e-books is $4.95, plus $3.99 per book downloaded. Write an equation that represents the total cost, c, in a month when b books are downloaded. Explain how your equation represents the problem.
When there are no books, the service fee still applies, so when b=0, c=$4.95. For each book downloaded $3.99 is added to the charge. The service fee is only charged once a month.
