1) the first factor, 3 means, that it costs $3.00 per video starting with the sixth video Ricardo rents. 2) the variable r represents the number of videos that Ricardo rents each month.3) the five represents the number of videos he can rent for free. I know this because it is being subtracted from the number of videos he rented in a particular month. So, for example, if he rents 25 videos, he pays for only 20.
hope this helps :)