document.write( "Question 507164: john's father is now twice as old as he is. 8 years ago, he was thrice as old. How old is each now? \n" ); document.write( "
Algebra.Com's Answer #340784 by Maths68(1474)\"\" \"About 
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Let
\n" ); document.write( "Present age of father = f
\n" ); document.write( "Present age of John = j
\n" ); document.write( "john's father is now twice as old as he is
\n" ); document.write( "f=2j ..........(1)
\n" ); document.write( "8 years ago means we have to subtract 8 from their present ages
\n" ); document.write( "f-8=j-8
\n" ); document.write( "then, he was thrice as old.
\n" ); document.write( "f-8=3(j-8)
\n" ); document.write( "f-8=3j-24
\n" ); document.write( "f=3j-24+8
\n" ); document.write( "f=3j-16...........(2)\r
\n" ); document.write( "\n" ); document.write( "Put the value of f from (1) to (2)
\n" ); document.write( "f=3j-16...........(2)
\n" ); document.write( "2j=3j-16
\n" ); document.write( "2j-3j=-16
\n" ); document.write( "-j=-16
\n" ); document.write( "Multiply by -1 both sides of the equation
\n" ); document.write( "-1*-j=-1*-16
\n" ); document.write( "j=16
\n" ); document.write( "Put the value of j in (1)
\n" ); document.write( "f=2j ..........(1)
\n" ); document.write( "f=2(16)
\n" ); document.write( "f=32\r
\n" ); document.write( "\n" ); document.write( "Present age of father = f = 32 years old
\n" ); document.write( "Present age of John = j = 16 years old\r
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