document.write( "Question 847024: The son is 21 years younger than the mother. In six years she will be five times as old as him. What age will the son be?
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Algebra.Com's Answer #510089 by Fombitz(32388) $\"\"$ $\"About$

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Something is wrong with your problem setup.
\n" ); document.write( " $\"S=M-21\"$
\n" ); document.write( "In 6 years, she will be M+6 and the son will be S+6.
\n" ); document.write( " $\"M%2B6=5%28S%2B6%29\"$
\n" ); document.write( "Substitute eq. 1 into eq. 2,
\n" ); document.write( " $\"M%2B6=5%28M-21%2B6%29\"$
\n" ); document.write( " $\"M%2B6=5%28M-15%29\"$
\n" ); document.write( " $\"M%2B6=5M-75\"$
\n" ); document.write( " $\"4M=81\"$
\n" ); document.write( " $\"M=81%2F4\"$
\n" ); document.write( "Then the son would be,
\n" ); document.write( " $\"S=81%2F4-21\"$
\n" ); document.write( " $\"S=81%2F4-84%2F4\"$
\n" ); document.write( " $\"S=-3%2F4\"$
\n" ); document.write( "Typically the solutions are integers first off and secondly no negative ages are allowed.
\n" ); document.write( "I also changed the problem in case the mother is five times older than his age today.
\n" ); document.write( " $\"M%2B6=5S\"$
\n" ); document.write( "Then,
\n" ); document.write( " $\"M%2B6=5%28M-21%29\"$
\n" ); document.write( " $\"M%2B6=5M-105\"$
\n" ); document.write( " $\"4M=111\"$
\n" ); document.write( " $\"M=111%2F4\"$
\n" ); document.write( "and then
\n" ); document.write( " $\"S=111%2F4-84%2F4\"$
\n" ); document.write( " $\"S=27%2F4\"$
\n" ); document.write( "Again typically the solutions are in integers values.
\n" ); document.write( "Please check the problem and repost if needed. \n" ); document.write( "

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