Question

Best Buy sells CDs and DVDs. Jose bought 3 CDs and 2 DVDs for $58. Lisbeth bought 1 CD and 4 DVDS for $46. Determined the selling price for each.

Answer 1

x = CD

y = DVD

Jose: 3x + 2y = 58

Lisbeth: x + 4y = 46

We can use substitution to solve:

x + 4y = 46 subtract 4 from both sides:

x = 46 - 4y

Plug this into the first equation:

3(46 - 4y) + 2y = 58

138 - 12y + 2y = 58

138 - 10y = 58

-10y = -80

y = 8

Plug this into the second equation:

x + 4(8) = 46

x + 32 = 46

x = 14

DVDs cost $8 and CDs cost $14