document.write( "Question 459136: Three years ago, Jeffrey was twice as old as Michael is now. In nine years, Jeffery will be four times as old as Michael is now. What are Jeffery's and Michael's current age. \n" ); document.write( "

Algebra.Com's Answer #314880 by oberobic(2304) $\"\"$ $\"About$

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Start by defining what their ages are now.
\n" ); document.write( "J = Jeffrey
\n" ); document.write( "M = Michael
\n" ); document.write( ".
\n" ); document.write( "Three years ago means -3.
\n" ); document.write( "Jeffrey was twice as old as Michael is now.
\n" ); document.write( "J-3 = 2M
\n" ); document.write( ".
\n" ); document.write( "In nine year means +9.
\n" ); document.write( "J+9 = 4M
\n" ); document.write( ".
\n" ); document.write( "Set up the linear equations.
\n" ); document.write( "J -2M = 3
\n" ); document.write( "J - 4M = -9
\n" ); document.write( "..
\n" ); document.write( "Subtract the second from the first.
\n" ); document.write( "2M = 12
\n" ); document.write( "M = 6
\n" ); document.write( ".
\n" ); document.write( "Substitute.
\n" ); document.write( "J-3 = 12
\n" ); document.write( "J = 15
\n" ); document.write( ".
\n" ); document.write( "Always check your work!
\n" ); document.write( "In this case, use the second equation.
\n" ); document.write( "J+9 = 4M
\n" ); document.write( "J+9 = 15+9 =24
\n" ); document.write( "4M = 4*6 = 24
\n" ); document.write( "Right.
\n" ); document.write( ".
\n" ); document.write( "Answer: Jeffrey is 15, and Michael is 6.
\n" ); document.write( ".
\n" ); document.write( "Done. \n" ); document.write( "

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