document.write( "Question 1011836: A bag of coins contains 57 nickels and dimes. The value of coins is $3.95
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Algebra.Com's Answer #627628 by AnlytcPhil(1806)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Let the number of nickels be x\r\n" );
document.write( "Let the number of dimes be y\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" );
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document.write( "nickels       x      $0.05     $0.05x\r\n" );
document.write( "dimes         y      $0.10     $0.10y\r\n" );
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document.write( "TOTALS       57      -----     $3.95\r\n" );
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document.write( " The first equation comes from the \"Number of coins\"\r\n" );
document.write( " column.\r\n" );
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document.write( "  \"%28matrix%283%2C1%2CNumber%2Cof%2Cnickels%29%29\"\"%22%22%2B%22%22\"\"%28matrix%283%2C1%2CNumber%2Cof%2Cdimes%29%29\"\"%22%22=%22%22\"\"%28matrix%284%2C1%2Ctotal%2Cnumber%2Cof%2Ccoins%29%29\"\r\n" );
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document.write( "                  x + y = 57\r\n" );
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document.write( " The second equation comes from the last column.\r\n" );
document.write( "  \"%28matrix%284%2C1%2CValue%2Cof%2CALL%2Cnickels%29%29\"\"%22%22%2B%22%22\"\"%28matrix%284%2C1%2CValue%2Cof%2CALL%2Cdimes%29%29\"\"%22%22=%22%22\"\"%28matrix%285%2C1%2CTotal%2Cvalue%2Cof%2CALL%2Ccoins%29%29\"\r\n" );
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document.write( "           0.05x + 0.10y = 3.95\r\n" );
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document.write( "Get rid of decimals by multiplying every term by 100:\r\n" );
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document.write( "               5x + 10y = 395\r\n" );
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document.write( " So we have the system of equations:\r\n" );
document.write( "           \"system%28x+%2B+y+=+57%2C5x+%2B+10y+=+395%29\".\r\n" );
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document.write( "We solve by substitution.  Solve the first equation for y:\r\n" );
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document.write( "           x + y = 57\r\n" );
document.write( "               y = 57 - x\r\n" );
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document.write( "Substitute (57 - x) for y in 5x + 10y = 395\r\n" );
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document.write( "    5x + 10(57 - x) = 395\r\n" );
document.write( "     5x + 570 - 10x = 395\r\n" );
document.write( "          -5x + 570 = 395\r\n" );
document.write( "                -5x = -175\r\n" );
document.write( "                  x = 35 = the number of nickels.\r\n" );
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document.write( "Substitute in y = 57 - x\r\n" );
document.write( "              y = 57 - (35\r\n" );
document.write( "              y = 22 dimes.\r\n" );
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document.write( "Checking:  35 nickels is $1.75 and 22 dimes is $2.20\r\n" );
document.write( "            That's 57 coins.\r\n" );
document.write( "            And indeed $1.75 + $2.20 = $3.95\r\n" );
document.write( "Edwin

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