a used bookstore also started selling used CDs and videos. In the first week the store sold a combination of 40 CDs and videos. They charged $4 CD and $6 per video and the total sales were $180. Determine the total number of CDs and videos sold
Accepted Solution
A:
First we must make a system of equations: c+v=40 4c+6v=180
We can solve this system of equations using substitution c+v=40 -v -v _________ c=40-v