Question

Edwin bought 3 cd's and 7 dvds for 80$. Jessica bought 6 cds and 3 dvds for 63.75$. Write a system of linear equations that could be used to deterime the cost of one cd and the cost of one dvd.

Answer 1

Let's assume that the cost of one CD is $x and the cost of one DVD is $y.

For Edwin:
3 CDs + 7 DVDs = $80
3x + 7y = 80

For Jessica:
6 CDs + 3 DVDs = $63.75
6x + 3y = 63.75

So, the system of linear equations is:
3x + 7y = 80
6x + 3y = 63.75