Question

A used book store is selling 3 records and 5 CDs for $60. You can also buy 6 records and 4 CDs for $80. Find the cost of one CD. Write the linear system that describes this situation.​

Answer 1

9514 1404 393

Answer:

3r +5c = 60

6r +4c = 80

Explanation:

There are many aspects of "this situation" that could be described by equations. We are guessing that you want equations that will help you determine the costs of a record and a CD, assuming the costs are the same for each instance of the media.

Let r and c represent the costs of a record and a CD, respectively.

3r +5c = 60 . . . . . . . the value of the first purchase

6r +4c = 80 . . . . . . . the value of the second purchase

These equations comprise a linear system describing an aspect of the situation.

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Comment on the question

The numbers make no sense, as the cost of a CD is $(6 2/3), the cost of a record is $(8 8/9).