document.write( "Question 1130667: six years ago a man was four times as old as his son was then. in twelve years, the many will be just twice as old as his son will be then. Find their present ages. \n" ); document.write( "

Algebra.Com's Answer #747290 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+a+\"$ = man's age now
\n" ); document.write( "Let $\"+b+\"$ = son's age now
\n" ); document.write( "---------------------------------
\n" ); document.write( "(1) $\"+a+-+6+=+4%2A%28+b+-+6+%29+\"$
\n" ); document.write( "(2) $\"+a+%2B+12+=+2%2A%28+b+%2B+12+%29+\"$
\n" ); document.write( "---------------------------------
\n" ); document.write( "(1) $\"+a+-+6+=+4b+-+24+\"$
\n" ); document.write( "(1) $\"+-a+%2B+4b+=+18+\"$
\n" ); document.write( "and
\n" ); document.write( "(2) $\"+a+%2B+12+=+2b+%2B+24+\"$
\n" ); document.write( "(2) $\"+a+-+2b+=+12+\"$
\n" ); document.write( "Add the equations
\n" ); document.write( " $\"+2b+=+30+\"$
\n" ); document.write( " $\"+b+=+15+\"$
\n" ); document.write( "and
\n" ); document.write( "(1) $\"+a+-+6+=+4%2A%28+15+-+6+%29+\"$
\n" ); document.write( "(1) $\"+a+-+6+=+36+\"$
\n" ); document.write( "(1) $\"+a+=+42+\"$
\n" ); document.write( "---------------------
\n" ); document.write( "The man is 42
\n" ); document.write( "His son is 15
\n" ); document.write( "---------------------
\n" ); document.write( "check:
\n" ); document.write( "(1) $\"+a+-+6+=+4%2A%28+b+-+6+%29+\"$
\n" ); document.write( "(1) $\"+42+-+6+=+4%2A%28+15+-+6+%29+\"$
\n" ); document.write( "(1) $\"+36+=+4%2A9+\"$
\n" ); document.write( "(1) $\"+36+=+36+\"$
\n" ); document.write( "OK
\n" ); document.write( "Check other equation
\n" ); document.write( " \n" ); document.write( "

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