caseylgreenday1 caseylgreenday1 07-09-2022 Mathematics contestada Recycled CDs, Incorporated, offers a choice of 5 used CDs for $21, with each additional CD costing $7. Write a cost function for purchasing 5 or more CDs. What will the cost of buying 12 CDs be? Let x represent the number of CDs over 5. C(x) =