Basic word problem for algebra 2 don't know how to do it

Question

at a music store compact discs cost 13.95 each are on sale for 10.95 if you spent 146.40 on 12 compact discs how many regular prices and sale prices discs did you buy?

Answer 1

Jared,

 

Assume you bought x CD's at regular price

 

Then you have 12-x CD's at sale price

 

Total cost to you = x*13.95 + (12-x)*10.95 = 146.40

 

13.95x -10.95 x + 131.4 = 146.4

 

3x = 15, x = 5

 

So you had 5 CD's at regular price and 7 at sales price.