document.write( "Question 262873: The sum of the ages of three sisters, Carol, Cindy, and Lisa, is 42. Carol, the oldest, is 4 times as old as Lisa, who is the youngest. How old is Cindy? Explain how you know. \n" ); document.write( "
Algebra.Com's Answer #193962 by ankor@dixie-net.com(22740)\"\" \"About 
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The sum of the ages of three sisters, Carol, Cindy, and Lisa, is 42.
\n" ); document.write( "Carol, the oldest, is 4 times as old as Lisa, who is the youngest.
\n" ); document.write( " How old is Cindy? Explain how you know.
\n" ); document.write( ":
\n" ); document.write( "let x, y, z = the three sisters, x is youngest, z the oldest
\n" ); document.write( ":
\n" ); document.write( "x + y + z = 42
\n" ); document.write( ":
\n" ); document.write( "The oldest (z) 4 times the youngest (x)
\n" ); document.write( "z = 4x
\n" ); document.write( ":
\n" ); document.write( "Replace z with 4x in the sum equation
\n" ); document.write( "x + y + 4x = 42
\n" ); document.write( "y + 5x = 42
\n" ); document.write( "y = 42 - 5x
\n" ); document.write( ":
\n" ); document.write( "Some values for this equation:
\n" ); document.write( "x | y
\n" ); document.write( "-----
\n" ); document.write( "2 |32
\n" ); document.write( "4 |22
\n" ); document.write( "5 |17
\n" ); document.write( "6 |12
\n" ); document.write( "7 | 7
\n" ); document.write( "8 | 2
\n" ); document.write( ":
\n" ); document.write( "know y<4x and y>x, only two values for x will satisfy this:
\n" ); document.write( "x=5, y=17, z=20
\n" ); document.write( "and
\n" ); document.write( "x=6, y=12, z=24
\n" ); document.write( ":
\n" ); document.write( "Two solutions,
\n" ); document.write( " Cindy is age 17, or Cindy is age 12\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "
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