document.write( "Question 931175: Can the sum of two 2 digit numbers be a 4 digit number? please explain how. \n" ); document.write( "

Algebra.Com's Answer #565470 by Edwin McCravy(20060) $\"\"$ $\"About$

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Every 2 digit number is greater than 9 and less than 100\r\n" );
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document.write( "Let M and N be two two-digit numbers, then\r\n" );
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document.write( " 9 < M < 100\r\n" );
document.write( " 9 < N < 100\r\n" );
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document.write( "We add those two inequalities term by term:\r\n" );
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document.write( " 9 <  M  < 100\r\n" );
document.write( " 9 <  N  < 100\r\n" );
document.write( "------------\r\n" );
document.write( "18 < M+N < 200\r\n" );
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document.write( "So their sum is always greater than 18 and less than 200,\r\n" );
document.write( "so their sum can never be a 4 digit number.  That's because\r\n" );
document.write( "4-digit numbers are all greater than 999.\r\n" );
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document.write( "Edwin

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