Posted by Faith on Wednesday, April 9, 2014 at 9:01pm.
A vendor at a concert sells new and used CDs. The new CDs cost 2.5 times as much as the old CDs. If 4 used CDs and 9 new CDs cost $159, what is the price of each item?

Math  bobpursley, Wednesday, April 9, 2014 at 9:17pm
9N+4U=159
9(2.5U)+ 4U=159
solve for U first, then solve for N