Question

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 justify a membership?

Answer 1

You need to rent 14 videos, and you'll pay the same amount for both. Renting 15 will make the membership a better method of payment.

Explanation:

Let Number of videos to be rented be x;

Given:

For non members;

Cost of renting 1 video = $4

Cost for renting x videos =
`4x`

For Members;

Membership cost = $21

Cost of renting 1 video = $2.50

Cost of renting x video =
`2.5x`

We can create an equation. Say the number of videos you rent is given by x . We can write that, if we rent x videos without membership, we'll have to pay
`4x` . If we rent the same amount of videos with membership, we'll have to pay
`21+2.5x`.

Hence the equation can written as

`4x=21+2.5x\\4x-2.5x=21\\1.5x=21\\x=(21)/(1.5)=14`

Hence You need to rent 14 videos, and you'll pay the same amount for both. Renting 15 will make the membership a better method of payment.