![\"\"](\"/images/stars/stars-13.gif\")
You can put this solution on YOUR website!
Call Jeanne's age J and call Michael's age M.
\n" ); document.write( ".
\n" ); document.write( "The problem tells you that Jeanne is 3 times Michael's age. In equation form this is:
\n" ); document.write( ".
\n" ); document.write( "J = 3*M
\n" ); document.write( ".
\n" ); document.write( "The problem also tells you that the sum of their ages is 20. In equation form this is:
\n" ); document.write( ".
\n" ); document.write( "J + M = 20
\n" ); document.write( ".
\n" ); document.write( "There are two unknowns and therefore we need two equations to solve for these unknowns.
\n" ); document.write( "We have our two equations.
\n" ); document.write( ".
\n" ); document.write( "As a result of our first equation we known that J = 3*M. Therefore, we can substitute
\n" ); document.write( "3*M for J in our second equation. When we do that the second equation becomes:
\n" ); document.write( ".
\n" ); document.write( "3*M = M = 20
\n" ); document.write( ".
\n" ); document.write( "Adding the terms on the left side results in:
\n" ); document.write( ".
\n" ); document.write( "4*M = 20
\n" ); document.write( ".
\n" ); document.write( "Dividing both sides of this equation by 4 tells us that:
\n" ); document.write( ".
\n" ); document.write( "M = 5
\n" ); document.write( ".
\n" ); document.write( "So we know that Michael's age is 5. And since Jeanne is 3 times as old as Michael,
\n" ); document.write( "then Jeanne must be 15.
\n" ); document.write( ".
\n" ); document.write( "Finally, as a check, you can note that the sum of their ages (5 + 15) is 20, which is
\n" ); document.write( "exactly what the problem said it should be.
\n" ); document.write( ".
\n" ); document.write( "Hope this helps you to understand how to translate this word problem into equations,
\n" ); document.write( "and then how to solve the equations to get the answer. \n" ); document.write( "