Question

A music store is offering a Frequent Buyers Club membership. The membership
costs $22 per year, and then a member can buy CDs at a reduced price. If a
member buys 17 CDs in one year, the cost is $111.25.

Determine the cost of each CD for a single member and then write a linear
equation to represent the total cost y of a one year membership, if x CDs are
purchased.

Answer 1

Now this person who buys the 17 CDs is a member.
And thus from the $111.25 he paid. A part is for the membership.

So Cost of 17 CDs is = Total Cost - cost of membership
= $111.25 - $22
= x [find the value]

And now if 17 CDs cost = x
One CD would cost = x/17

Understood till here? :)

Answer 2

@Mr. batman ?

Answer 3

not really but kind of

Answer 4

What did you NOT understand there?

Answer 5

Let me try to help you out here! :D

Answer 6

so it just 111.25 - $22 ?

Answer 7

I don't get it, is it y=89x-22

Answer 8

The question WANTS you to think about the cost.

It says, "If a MEMBER buys 17 CDs in one year, the cost is $111.25."
So if a member buys it. He has to pay for the MEMBERSHIP charges ALSO.

So cost of 17 CDs + Cost of Membership = $111.25
Thus the cost of 17CDs would be = $111.25 - $22 [the membership charge]

The cost of 17CDs = $111.25 - $22 = $89.25




Let us take one example now:
Say you pay 100 dollars for 10 candies
How much then are you paying for ONE?

Thus one candy = 100 dollars/10 candies. = 10 dollars.

Thus one candy costs 10 dollars.



Now let us return back to our example:
We have 17 CDs now for 89.25 dollars
How much would you pay for ONE?
Thus ONE CD costs 89.25 dollars/the 17 CDs. = 5.25 dollars.

Got it till here? :D

Answer 9

wait how do you get 89 ?

Answer 10

Thus the cost of 17CDs would be = $111.25 - $22 [the membership charge]

The cost of 17CDs = $111.25 - $22 = $89.25

Answer 11

so how do you get the equation

Answer 12

Now you have to generalize the thing

Now you know that one CD costs = $5.25
Then if x CDs are purchased, the CDs'll cost you = $(5.25 * x)

Cost of one year membership = $22

Total cost = y = cost of membership + cost of x CDs
Thus, the linear equation in 2 variables x and y is

=> y = 22 + 5.25x

Understood? :D