document.write( "Question 336555: The sum of the ages of a brother and sister is 29. If four times the brother's age is subtracted from three times the sister's age, the difference is 24. \n" ); document.write( "

Algebra.Com's Answer #241327 by Fombitz(32388) $\"\"$ $\"About$

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Let $\"B\"$ be the brother's age, $\"S\"$ the sister's.
\n" ); document.write( "1. $\"S%2BB=29\"$
\n" ); document.write( "2. $\"3S-4B=24\"$
\n" ); document.write( "Multiply eq. 1 by 4 and add the equations together,
\n" ); document.write( " $\"4S%2B4B%2B3S-4B=116%2B24\"$
\n" ); document.write( " $\"7S=140\"$
\n" ); document.write( " $\"highlight%28S=20%29\"$
\n" ); document.write( "From eq. 1,
\n" ); document.write( " $\"B=29-20\"$
\n" ); document.write( " $\"highlight%28B=9%29\"$
\n" ); document.write( " \n" ); document.write( "

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