For members a video store charges a membership fee of $21 and then $2.50 for each movie rental. For non-members they charge $4 for each movie rental. How many movies do you need to rent for members and non-members to pay the same amount?
Both of these will be the same when Customers have rented 14 videos.
Let's call the number of videos we are looking for
For non-member these videos would cost:
For members these videos would cost the membership fee plus the $2.50 per video or: #$21 + ($2.50 xx v).
To find when these are equal you equate them and solve as follows: