document.write( "Question 519229: The age of the father is 5 times the age of his son. After 18 years, the age of the father will be twice his sons age. Find their present ages. \n" ); document.write( "
Algebra.Com's Answer #345456 by Maths68(1474)\"\" \"About 
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Let
\n" ); document.write( "Present age of Father = f
\n" ); document.write( "Present age of Son = s\r
\n" ); document.write( "\n" ); document.write( "The age of the father is 5 times the age of his son.
\n" ); document.write( "f=5s.........(1)\r
\n" ); document.write( "\n" ); document.write( "After 18 years,
\n" ); document.write( "Age of Father = f+18
\n" ); document.write( "Age of Son = s+18
\n" ); document.write( "Then, the age of the father will be twice his sons age.
\n" ); document.write( "f+18=2(s+18)
\n" ); document.write( "f+18=2s+36
\n" ); document.write( "f=2s+36-18
\n" ); document.write( "f=2s+18............(1)
\n" ); document.write( "Substitute the value of f in (2) from (1)
\n" ); document.write( "5s=2s+18
\n" ); document.write( "5s-2s=18
\n" ); document.write( "3s=18
\n" ); document.write( "3s/3=18/3
\n" ); document.write( "s=6
\n" ); document.write( "Substitute the value of s in (1)
\n" ); document.write( "f=5s
\n" ); document.write( "f=5(6)
\n" ); document.write( "f=30
\n" ); document.write( " \r
\n" ); document.write( "\n" ); document.write( "Present age of Father = f = 30 years old
\n" ); document.write( "Present age of Son = s = 6 years old
\n" ); document.write( " \n" ); document.write( "
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