SOLUTION: Mary bought 6 new compact disks and 2 used compact disks for $127.92. At the same prices, Neal bought 3 new compact disks and 8 used compact disks for $133.89. Find the cost of buy

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Mary bought 6 new compact disks and 2 used compact disks for $127.92. At the same prices, Neal bought 3 new compact disks and 8 used compact disks for $133.89. Find the cost of buy      Log On


   

Question 1106191: Mary bought 6 new compact disks and 2 used compact disks for $127.92. At the same prices, Neal bought 3 new compact disks and 8 used compact disks for $133.89. Find the cost of buying a single used compact disk.
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +a+ = the cost of a single new CD
Let +b+ = the cost of a single used CD
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(1) +6a+%2B+2b++=+127.92+
(2) +3a+%2B+8b+=+133.98+
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Multiply both sides of (1) by +4+
and subtract (2) from (1)
You can finish