document.write( "Question 918248: Robyn's piggy bank contains fifty coins in dimes and quarters. The coins have a total value of $8.60. Find the number of dimes and quarters in the piggy bank. \n" ); document.write( "

Algebra.Com's Answer #556996 by Edwin McCravy(20056) $\"\"$ $\"About$

You can put this solution on YOUR website!

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document.write( "Let the number of dimes be x.\r\n" );
document.write( "Then the number of quarters, \r\n" );
document.write( "using ONE PART = TOTAL MINUS OTHER PART,\r\n" );
document.write( "  is 50-x. \r\n" );
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document.write( "Make this chart:\r\n" );
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document.write( "                      Value      Value\r\n" );
document.write( "Type       Number       of         of\r\n" );
document.write( " of          of        EACH       ALL\r\n" );
document.write( "coin        coins      coin      coins\r\n" );
document.write( "-------------------------------------------\r\n" );
document.write( "DIMES         x        $0.10    $0.10x \r\n" );
document.write( "QUARTERS    50-x       $0.25    $0.25(50-x)\r\n" );
document.write( "-------------------------------------------\r\n" );
document.write( "TOTALS       50        -----    $8.60\r\n" );
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document.write( " 0.10x + 0.25(50-x) = 8.60\r\n" );
document.write( "Get rid of decimals by multiplying every term by 100\r\n" );
document.write( "     10x + 25(50-x) = 860   \r\n" );
document.write( "   10x + 1250 - 25x = 860\r\n" );
document.write( "        -15x + 1250 = 860\r\n" );
document.write( "              -15x = -390\r\n" );
document.write( "                 x = 26 = the number of dimes\r\n" );
document.write( "The number of quarters is 50-x or 50-26 or 24 quarters.\r\n" );
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document.write( "Checking: 26 dimes + 24 quarters = 50 coins. That checks.\r\n" );
document.write( "26 dimes is worth $2.60 and 24 quarters is worth $6.00.\r\n" );
document.write( "That adds to $8.60.  That checks.  So we are right.\r\n" );
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document.write( "Edwin

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