document.write( "Question 1042269: A bag contains 100 cards with letters on them. There are 50 cards with a letter A on them, 25 cards with a letter B, and 40 cards with a letter C.
\n" ); document.write( "Referring to the scenario above, if only 10 cards have both letters A and B, how many cards definitely have only the letter C and NOT the letter A or B? \n" ); document.write( "
Algebra.Com's Answer #657278 by Edwin McCravy(20056)\"\" \"About 
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document.write( "So\r\n" );
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document.write( "d+e+f+g+h+i+j = 100\r\n" );
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\n" ); document.write( "There are 50 cards with a letter A on them,
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document.write( "d+e+g+h = 50\r\n" );
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\n" ); document.write( "25 cards with a letter B,
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document.write( "e+f+h+i = 25\r\n" );
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\n" ); document.write( "and 40 cards with a letter C.
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document.write( "g+h+i+j = 40\r\n" );
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\n" ); document.write( "Referring to the scenario above, if only 10 cards
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document.write( "e + h = 10\r\n" );
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\n" ); document.write( "How many cards definitely have only the letter C
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document.write( "We want only the value of j.\r\n" );
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document.write( "So we have this system of equations:\r\n" );
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document.write( "Multiply eq.1 by -1\r\n" );
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document.write( "Add eq. 1 to eq. 2 \r\n" );
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document.write( "Multiply eq. 3 by -1\r\n" );
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document.write( "Add equation 5 to eq. 3\r\n" );
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document.write( "  \r\n" );
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document.write( "Multiply equation 2 by -1\r\n" );
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document.write( "Add eq. 3 to eq. 2:\r\n" );
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document.write( "The second equation tells us that j = 35.\r\n" );
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document.write( "The other tutor is correct.\r\n" );
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document.write( "Edwin

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