document.write( "Question 870728: Remain is seven times as old as his son. 10 years hence he will be three times as old as his son. What are their present ages in years? \n" ); document.write( "

Algebra.Com's Answer #525090 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+s+\"$ = his son's age now
\n" ); document.write( " $\"+7s+\"$ = Remain's age now
\n" ); document.write( " $\"+s+%2B+10+\"$ = his son's age in 10 years
\n" ); document.write( " $\"+7s+%2B+10+\"$ = Remain's age in 10 years
\n" ); document.write( "------------------------------------
\n" ); document.write( " $\"+7s+%2B+10+=+3%2A%28+s+%2B+10+%29+\"$
\n" ); document.write( " $\"+7s+%2B+10+=+3s+%2B+30+\"$
\n" ); document.write( " $\"+4s+=+20+\"$
\n" ); document.write( " $\"+s+=+5+\"$
\n" ); document.write( "and
\n" ); document.write( " $\"+7s+=+7%2A5+\"$
\n" ); document.write( " $\"+7s+=+35+\"$
\n" ); document.write( "----------------
\n" ); document.write( "His son's age now is 5
\n" ); document.write( "Remain's age now is 35
\n" ); document.write( "-----------------------
\n" ); document.write( "check:
\n" ); document.write( " $\"+7s+%2B+10+=+3%2A%28+s+%2B+10+%29+\"$
\n" ); document.write( " $\"+7%2A5+%2B+10+=+3%2A%28+5+%2B+10+%29+\"$
\n" ); document.write( " $\"+35+%2B+10+=+3%2A15+\"$
\n" ); document.write( " $\"+45+=+45+\"$
\n" ); document.write( "OK
\n" ); document.write( " \n" ); document.write( "

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