SOLUTION: Suppose a video store charges non-members $4 to rent a video. A membership costs $21 and then videos cost only $2.50 to rent. How many videos would you need to rent in order to jus

Algebra ->  Expressions-with-variables -> SOLUTION: Suppose a video store charges non-members $4 to rent a video. A membership costs $21 and then videos cost only $2.50 to rent. How many videos would you need to rent in order to jus      Log On


   

Question 159971: Suppose a video store charges non-members $4 to rent a video. A membership costs $21 and then videos cost only $2.50 to rent. How many videos would you need to rent in order to jusitfy a membership?
Answer by jojo14344(1513) About Me  (Show Source):
You can put this solution on YOUR website!

Non member: ($4)(# of Vd)
Member: ($21)+($2.50)(# of Vd)
Equating the 2:
4%2AVd=21%2B2.50%2AVd EQN 1
4Vd-2.50Vd=21
1.5Vd=21 -----> cross%281.5%29Vd%2Fcross%281.5%29=cross%2821%2914%2Fcross%281.5%29
Vd=14 ---------------> no. of videos to rent should be MORE than 14 to justify membership.
Okay, plug in 14 to EQN 1:
4%2A14=21%2B2.50%2A14
56=21%2B35
56=56, see, at 14 rentals being a non member or a member will just be the same
Try 15 rentals:
4%2A15=21%2B2.50%2A15
60=21%2B37.50
60=58.50, see, the higher the rentals, you start to save on being a member.
Try 20 for yourself.
Thank you,
Jojo