document.write( "Question 800698: The cost of five cassettes and two cds is $65. If you buy three cassettes and four cds the cost is $81. find the cost of each cassette and cd. \n" ); document.write( "

Algebra.Com's Answer #483205 by mananth(16946) $\"\"$ $\"About$

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x= cost of cassette
\n" ); document.write( "y= cost of CD
\n" ); document.write( "
\n" ); document.write( "5 x + 2 y = 65 .............1
\n" ); document.write( "Total value
\n" ); document.write( "3 x + 4 y = 81 .............2
\n" ); document.write( "Eliminate y
\n" ); document.write( "multiply (1)by -2
\n" ); document.write( "Multiply (2) by 1
\n" ); document.write( "-10 x -4 y = -130
\n" ); document.write( "3 x + 4 y = 81
\n" ); document.write( "Add the two equations
\n" ); document.write( "-7 x = -49
\n" ); document.write( "/ -7
\n" ); document.write( "x = 7
\n" ); document.write( "plug value of x in (1)
\n" ); document.write( "5 x + 2 y = 65
\n" ); document.write( "35 + 2 y = 65
\n" ); document.write( " 2 y = 65 -35
\n" ); document.write( " 2 y = 30
\n" ); document.write( " y = 15
\n" ); document.write( "x= $7 cost of cassette
\n" ); document.write( "y= $15 cost of CD
\n" ); document.write( "m.ananth@hotmail.ca
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