document.write( "Question 770384: Noah is 40, Mary is 13. How many years ago was Noah four times as old as Mary? \n" ); document.write( "

Algebra.Com's Answer #469519 by Edwin McCravy(20055) $\"\"$ $\"About$

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Noah is 40, Mary is 13. How many years ago was Noah four times as old as Mary?
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document.write( "Let the answer be \"x years ago\".\r\n" );
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document.write( "Noah's age x years ago = 40-x\r\n" );
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document.write( "Mary's age x years ago = 13-x\r\n" );
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document.write( "The equation comes from:\r\n" );
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document.write( "              \r\n" );
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document.write( "                40-x = 4(13-x)\r\n" );
document.write( "                40-x = 52-4x\r\n" );
document.write( "                  3x = 12\r\n" );
document.write( "                   x = 4\r\n" );
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document.write( "Answers: 4 years ago Noah was 36.  4 years age Mary was 9.\r\n" );
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document.write( "That checks because 36 is 4 times 9.\r\n" );
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document.write( "Edwin

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