document.write( "Question 665558: A man's age is four times that me his son. Seven years ago his age was eleven times that of his son. How old are they now? \n" ); document.write( "

Algebra.Com's Answer #413923 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+f+\"$ = Father's age now
\n" ); document.write( "Let $\"+s+\"$ = Son's age now
\n" ); document.write( " $\"+f+-+7+\"$ = Father's age 7 yrs ago
\n" ); document.write( " $\"+s+-+7+\"$ = Son's age 7 yrs ago
\n" ); document.write( "---------------------------
\n" ); document.write( "given:
\n" ); document.write( "(1) $\"+f+=+4s+\"$
\n" ); document.write( "(2) $\"+f+-+7+=+11%2A%28+s+-+7+%29+\"$
\n" ); document.write( "-----------------------
\n" ); document.write( "(2) $\"+f+-+7+=+11s+-+77+\"$
\n" ); document.write( "(2) $\"+f+=+11s+-70+\"$
\n" ); document.write( "Substitute (1) into (2)
\n" ); document.write( "(2) $\"+4s+=+11s+-70+\"$
\n" ); document.write( "(2) $\"+7s+=+70+\"$
\n" ); document.write( "(2) $\"+s+=+10+\"$
\n" ); document.write( "and, since
\n" ); document.write( "(1) $\"+f+=+4s+\"$
\n" ); document.write( "(1) $\"+f+=+4%2A10+\"$
\n" ); document.write( "(1) $\"+f+=+40+\"$
\n" ); document.write( "The father is 40 and the Son is 10
\n" ); document.write( "check answer:
\n" ); document.write( "(2) $\"+f+-+7+=+11%2A%28+s+-+7+%29+\"$
\n" ); document.write( "(2) $\"+40+-+7+=+11%2A%28+10+-+7+%29+\"$
\n" ); document.write( "(2) $\"+33+=+11%2A3+\"$
\n" ); document.write( "(2) $\"+33+=+33+\"$
\n" ); document.write( "OK
\n" ); document.write( " \n" ); document.write( "

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