document.write( "Question 1167121: Mary bought 10 gift cards in The denominations of $20, $50,$100. She spent $370. She has twice as many $20 gift cards as $50 gift cards. How many of each
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Algebra.Com's Answer #791713 by ikleyn(52867) $\"\"$ $\"About$

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\n" ); document.write( "Mary bought 10 gift cards in The denominations of $20, $50,$100. She spent $370.
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document.write( "Let x be the number of $50 cards.\r\n" );
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document.write( "Then the number of the $20 cards is 2x, and the number of the $100 cards is  (10-x-2x) = (10-3x).\r\n" );
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document.write( "Now you can write the money equation\r\n" );
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document.write( "    50x + 20*(2x) + 100*(10-3x) = 370  dollars.\r\n" );
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document.write( "Simplify and solve\r\n" );
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document.write( "    50x + 40x + 1000 - 300x = 370\r\n" );
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document.write( "    1000 - 370 = 300x - 50x - 40x\r\n" );
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document.write( "     630       = 210x\r\n" );
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document.write( "       x       = 630/210 = 3.\r\n" );
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document.write( "ANSWER.  3  $50-cards;  3*2 = 6  $20-cards  and  the rest  10- 3 - 6 = 1  $100-card. \r\n" );
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