SOLUTION: Have 7 DVDs and CDs, cost of DVD is $14.95, cost of CD is $16.88, total for 7 items is $114.30. How many CDs were bought and how many DVDs were bought?

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Question 223634: Have 7 DVDs and CDs, cost of DVD is $14.95, cost of CD is $16.88, total for 7 items is $114.30. How many CDs were bought and how many DVDs were bought?
Answer by RAY100(1637) About Me  (Show Source):
You can put this solution on YOUR website!
Let C=# CD's,,,,,,and D = # DVD's
.
C+D =7,,,,,,or C=7-D
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$ 16.88 C + $ 14.95 D = $ 114.30,,,,,,subst
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$ 16.88(7-D) + $ 14.95D = $ 114.30
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118.16 -16.88D +14.95D = 114.30
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118.16 - 1.93 D = 114.30
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-1.93 D = - 3.86
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D= 2,,,,,,,,,,C=7-2 = 5
.
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check,,,,16.88(5) + 14.95(2) = 114.30,,,,ok
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