Question 691123: Mary bought 4 tapes and 5 cd's for a total of $83. Mark bought 6 tapes and 3 cd's for a total of $75 . How much are tapes and cd's? Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! Mary bought 4 tapes and 5 cd's for a total of $83. Mark bought 6 tapes and 3 cd's for a total of $75 . How much are tapes and cd's?
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Equation:
4t + 5c = 83 dollars
6t + 3c = 75 dollars
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Multiply thru 1st by 3
Multiply thru 2nd by 5
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12t + 15c = 3*83
30t + 15c = 5*75
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Subtract and solve for "t":
18t = 126
t = $7 (price of each tape)
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Solve for "c" using 4t + 5c = 83 dollars
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4*7 + 5c = 83
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5c = 83-28
5c = 55
c = $11 (price of a cd)
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Cheers,
Stan H.
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