Question

A video rental store charges a $20 membership fee and $2.50 for each video rented. Write and graph a linear equation (y=mx+b) to model this situation. If 15 videos are rented, what is the revenue? If a new member paid the store $67.50 in the last 3 months, how many videos were rented?

Answer 1

19 Videos

Explanation:

If she paid the store $67.50 (USD) and the membership is 20$ take that 20 and add 2.50 onto it till you get the answer BUT if you want to explain it all the way each month has about 30 days in it so 30x3=90 so she was there for 90 days. 90x$2.50=225 but we all know, she couldn't have rented that many... right? but the final answer is 19, you take 20 from 67.50 which was the membership and all you have to do is fill in that missing amount so take 2.50 and multiply till you get the answer.

Answer 2

Part 1 : Given,

Membership fees = $ 20,

Also, the charges for each video = $ 2.50,

Thus, the total charges for x videos( say y ) = 20 + 2.5x

⇒ y = 20 + 2.5x

Which is the required equation.

Graphing :

if x = 0, y = 20,

if y = 0, 2.5x = -20 ⇒ x = -8,

Join the points (0, 20) and (-8, 0),

Part 2 : If x = 15 videos,

Thus, the total revenue,

y = 20 + 2.5(15) = 20 + 37.5 = $ 57.5,

Part 3 : If y = 67.5,

67.5 = 20 + 2.5x

47.5 = 2.5x

⇒ x = 19

Hence, 19 videos were rented.