document.write( "Question 190312: Ten years ago a father was seven times as old as his son, two years hence twice
\n" ); document.write( "his age will be equal to five times his son's age. What are their present ages? \n" ); document.write( "
Algebra.Com's Answer #142924 by ankor@dixie-net.com(22740)\"\" \"About 
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Ten years ago a father was seven times as old as his son, two years hence
\n" ); document.write( " twice his age will be equal to five times his son's age.
\n" ); document.write( "What are their present ages?
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\n" ); document.write( "Let f = father's present age
\n" ); document.write( "Let s = son's present age
\n" ); document.write( ":
\n" ); document.write( "Write an equation & simplify, for each statement:
\n" ); document.write( ":
\n" ); document.write( "\"Ten years ago a father was seven times as old as his son,\"
\n" ); document.write( "(f-10) = 7(s-10)
\n" ); document.write( "f - 10 = 7s - 70
\n" ); document.write( "f = 7s - 70 + 10
\n" ); document.write( "f = 7s - 60
\n" ); document.write( ";
\n" ); document.write( "\" two years hence twice his age will be equal to five times his son's age.\"
\n" ); document.write( "2(f + 2) = 5(s + 2)
\n" ); document.write( "2f + 4 = 5s + 10
\n" ); document.write( "2f = 5s + 10 - 4
\n" ); document.write( "2f = 5s + 6
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\n" ); document.write( " What are their present ages?
\n" ); document.write( "Substitute (7s-60) for f in the above equation:
\n" ); document.write( "2(7s - 60) = 5s + 6
\n" ); document.write( "14s - 120 = 5s + 6
\n" ); document.write( "14s - 5s = 6 + 120
\n" ); document.write( "9s = 126
\n" ); document.write( "s = \"126%2F9\"
\n" ); document.write( "s = 14 yr's is son's present age
\n" ); document.write( ":
\n" ); document.write( "find f using eq: f = 7s - 60
\n" ); document.write( "f = 7(14) - 60
\n" ); document.write( "f = 98 - 60
\n" ); document.write( "f = 38 yrs is father's present age
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\n" ); document.write( "Check solution's in the statement:
\n" ); document.write( "\"two years hence twice his age will be equal to five times his son's age.\"
\n" ); document.write( "2(38+2) = 5(14+2)
\n" ); document.write( "2(40) = 5(16) \n" ); document.write( "
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