A store sold 8/5 as many dvd's as cd's. the total number of dvd's and cds sold tha day was 273. how many dvd's were sold

If we call the number of DVDs x and the number of CDs y we can form two equations.

x=8/5*y and x+y=273

5x=8y and x=273-y

Now if we sub 273-y for x in the first equation:

5 (273-y) = 8y

1365=13y

y=105

x=273-105

x=168

168 DVDs were sold