document.write( "Question 162761: In the Independent Practice on pg 93, I am having difficulty setting up the equation for problem 2.\r
\n" ); document.write( "\n" ); document.write( "Jerome bought 12cds. Some cost 7.50 ea. the rest cost 6.50 each. How many CDs were bought at each price if he spent $82? \n" ); document.write( "
Algebra.Com's Answer #120031 by orca(409)\"\" \"About 
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Let x be the number of cds that cost $7.5 each.
\n" ); document.write( "Let y be the number of cds that cost $6.5 each.
\n" ); document.write( "The money spent on the $7.5 cds is 7.5x
\n" ); document.write( "The money spent on the $6.5 cds is 6.5y.
\n" ); document.write( "Now use the following relationships to set up a system of two equations:
\n" ); document.write( "(1) the total number of cds = 12
\n" ); document.write( "(2) the total money spent = 82\r
\n" ); document.write( "\n" ); document.write( "So
\n" ); document.write( "x + y = 12 ..............(1)
\n" ); document.write( "7.5x + 6.5y = 82 ...........(2)\r
\n" ); document.write( "\n" ); document.write( "Solving equation (1) for y, we have
\n" ); document.write( "y = 12 - x ...............(3)
\n" ); document.write( "Substituting y = 12 - x into equation (2), we have
\n" ); document.write( "7.5x + 6.5(12 - x) = 82
\n" ); document.write( "Solving for x, we obtain:
\n" ); document.write( "7.5x + 78 - 6.5x = 82
\n" ); document.write( "x + 78 = 82
\n" ); document.write( "x = 4\r
\n" ); document.write( "\n" ); document.write( "Substituting x = 4 into equation (3) to find y, we get
\n" ); document.write( "y = 12 - x = 12 - 4 = 8\r
\n" ); document.write( "\n" ); document.write( "So Jerome bought 4 $7.5 cds, 8 $6.5 cds.\r
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