![\"\"](\"/images/stars/stars-13.gif\")
You can put this solution on YOUR website!
let x = matt's age.
\n" ); document.write( "let y = matt's father's age.
\n" ); document.write( "you get x = .4 * y
\n" ); document.write( "that's the current relationship between their ages.
\n" ); document.write( "in ten years, matt's age will be 50% of his father's age.
\n" ); document.write( "you get x + 10 = .5 * (y + 10)
\n" ); document.write( "that's the relationship of their ages 10 years from now.
\n" ); document.write( "you have two equations that need to be solved simultaneously.
\n" ); document.write( "they are:
\n" ); document.write( "x = .4 * y
\n" ); document.write( "x + 10 = .5 * (y + 10)
\n" ); document.write( "replace x with .4 * y in the second equation to get:
\n" ); document.write( ".4 * y + 10 = .5 * (y + 10)
\n" ); document.write( "simplify to get:
\n" ); document.write( ".4 * y + 10 = .5 * y + 5
\n" ); document.write( "subtract .4 * y from both sides of the equation and subtract 5 from both sides of the equation to get:
\n" ); document.write( "10 - 5 = .5 * y - .4 * y
\n" ); document.write( "combine like terms to get:
\n" ); document.write( "5 = .1 * y
\n" ); document.write( "solve for y to get:
\n" ); document.write( "y = 5 /.1 = 50
\n" ); document.write( "that's his father's age today.
\n" ); document.write( "his age today is .4 * 50 = 20.
\n" ); document.write( "in 10 years, matt will be 30 and his father will be 60.
\n" ); document.write( "that means that matt's age will be .5 * his father's age at that time.
\n" ); document.write( "your solution is that matt is 20 and his father is 50 today.
\n" ); document.write( "today, 20/50 = .4
\n" ); document.write( "10 years from now, 30/60 = .5\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "