document.write( "Question 420706: A father is 60 years old and his son is half his age. How old was the boy when his father was four times his age? \n" ); document.write( "

Algebra.Com's Answer #293895 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

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A father is 60 years old and his son is half his age.
\n" ); document.write( " How old was the boy when his father was four times his age?
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\n" ); document.write( "let y = years ago when dad's age was 4 times son's age
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\n" ); document.write( "60 - y = 4(30 - y)
\n" ); document.write( "60 - y = 120 - 4y
\n" ); document.write( "-y + 4y = 120 - 60
\n" ); document.write( "3y = 60
\n" ); document.write( "y = $\"60%2F3\"$
\n" ); document.write( "y = 20 years ago
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\n" ); document.write( "Then 30 - 20 = 10 yrs old, boy's age when his dad was 40 yrs old \n" ); document.write( "

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