document.write( "Question 441229: if bob is one third the age of his dad. in 12 years he will be half his age how old are they now? \n" ); document.write( "

Algebra.Com's Answer #304704 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

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Let b = Bob's present age
\n" ); document.write( "Let d = dad's present age
\n" ); document.write( ":
\n" ); document.write( "Write an equation for each statement:
\n" ); document.write( ":
\n" ); document.write( "\"bob is one third the age of his dad.\"
\n" ); document.write( "b = $\"1%2F3\"$ d
\n" ); document.write( "Multiply by 3 to get rid of the fraction, results
\n" ); document.write( "3b = d
\n" ); document.write( ":
\n" ); document.write( "\"in 12 years he will be half his age\"
\n" ); document.write( "b + 12 = $\"1%2F2\"$ (d+12)
\n" ); document.write( "multiply by 2, to get rid of the fraction, results
\n" ); document.write( "2(b+12) = d + 12
\n" ); document.write( "2b + 24 = d + 12
\n" ); document.write( "2b = d + 12 - 24
\n" ); document.write( "2b = d - 12
\n" ); document.write( "Replace d with 3b, from the 1st statement:
\n" ); document.write( "2b = 3b - 12
\n" ); document.write( "12 = 3b - 2b
\n" ); document.write( "b = 12 yrs is bob's present age
\n" ); document.write( ":
\n" ); document.write( "I'll let you find dad's age, check the solution in the 2nd statement\r
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