document.write( "Question 490883: the sum of ages of the son and his father is 69. if the father 's age is twice as his son's age increased by 9, find their present ages. \n" ); document.write( "
Algebra.Com's Answer #334566 by Maths68(1474)\"\" \"About 
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Let
\n" ); document.write( "f= father’s current age
\n" ); document.write( "s=son’s current age\r
\n" ); document.write( "\n" ); document.write( "the sum of ages of the son and his father is 69. \r
\n" ); document.write( "\n" ); document.write( "f+s=69
\n" ); document.write( "s=69-f………….(1)\r
\n" ); document.write( "\n" ); document.write( "son's age increased by 9 = s+9\r
\n" ); document.write( "\n" ); document.write( "Father 's age is twice as his son's age increased by 9 means
\n" ); document.write( "f=2(s+9)
\n" ); document.write( "f=2s+18…………(2)\r
\n" ); document.write( "\n" ); document.write( "Put the value of s from (1) to (2)
\n" ); document.write( "f=2(69-f)+18
\n" ); document.write( "f=138-2f+18
\n" ); document.write( "f=-2f+156
\n" ); document.write( "f+2f=156
\n" ); document.write( "3f=156
\n" ); document.write( "f=156/3
\n" ); document.write( "f=52\r
\n" ); document.write( "\n" ); document.write( "Put the value of f in (1)
\n" ); document.write( "s=69-f
\n" ); document.write( "s=69-52
\n" ); document.write( "s=17\r
\n" ); document.write( "\n" ); document.write( "Father is 52 and Son is 17 years old at present.
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