document.write( "Question 342360: please help me solve this: A father is four times as old as his son. In six years time,their combined ages will be 57. How old is the father now? \n" ); document.write( "

Algebra.Com's Answer #245022 by Fombitz(32388) $\"\"$ $\"About$

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Let the Father's age be $\"F\"$ , the son's $\"S\"$ .
\n" ); document.write( "In 6 years their ages are $\"F%2B6\"$ and $\"S%2B6\"$ .
\n" ); document.write( "1. $\"F=4S\"$
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\n" ); document.write( " $\"%28F%2B6%29%2B%28S%2B6%29=57\"$
\n" ); document.write( " $\"F%2BS%2B12=57\"$
\n" ); document.write( "2. $\"F%2BS=45\"$
\n" ); document.write( "Substitute eq. 1 into eq. 2,
\n" ); document.write( " $\"4S%2BS=45\"$
\n" ); document.write( " $\"5S=45\"$
\n" ); document.write( " $\"highlight%28S=9%29\"$ years old
\n" ); document.write( "Then from eq. 1,
\n" ); document.write( " $\"F=4%289%29\"$
\n" ); document.write( " $\"highlight%28F=36%29\"$ years old \n" ); document.write( "

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