document.write( "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? \n" ); document.write( "

Algebra.Com's Answer #426491 by stanbon(75887) $\"\"$ $\"About$

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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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\n" ); document.write( "Equation:
\n" ); document.write( "4t + 5c = 83 dollars
\n" ); document.write( "6t + 3c = 75 dollars
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\n" ); document.write( "Multiply thru 1st by 3
\n" ); document.write( "Multiply thru 2nd by 5
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\n" ); document.write( "12t + 15c = 3*83
\n" ); document.write( "30t + 15c = 5*75
\n" ); document.write( "-------
\n" ); document.write( "Subtract and solve for \"t\":
\n" ); document.write( "18t = 126
\n" ); document.write( "t = $7 (price of each tape)
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\n" ); document.write( "Solve for \"c\" using 4t + 5c = 83 dollars
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\n" ); document.write( "4*7 + 5c = 83
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\n" ); document.write( "5c = 83-28
\n" ); document.write( "5c = 55
\n" ); document.write( "c = $11 (price of a cd)
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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