document.write( "Question 1145724: The total length of three cross-country ski trails is 40km. The Yellow trail is 3km longer than twice the length of the Blue trail, and the Red trail is 10km shorter than twice the length of the Yellow trail. How long is each trail? \n" ); document.write( "
Algebra.Com's Answer #766985 by ankor@dixie-net.com(22740)\"\" \"About 
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The total length of three cross-country ski trails is 40km.\
\n" ); document.write( "y + b + r = 40
\n" ); document.write( " The Yellow trail is 3km longer than twice the length of the Blue trail,
\n" ); document.write( "y = 2b + 3
\n" ); document.write( " and the Red trail is 10km shorter than twice the length of the Yellow trail.
\n" ); document.write( "r = 2y - 10
\n" ); document.write( " How long is each trail?
\n" ); document.write( ":
\n" ); document.write( "rearrange the 2nd equation to:
\n" ); document.write( "2b = y - 3
\n" ); document.write( "b = .5y - 1.5
\n" ); document.write( "in the first equation, replace b with (.5y-1.5) and r with (2y-10)
\n" ); document.write( "y + (.5y-1.5) + (2y-10) = 40
\n" ); document.write( "3.5y - 11.5 = 40
\n" ); document.write( "3.5y = 40 + 11.5
\n" ); document.write( "3.5y = 51.5
\n" ); document.write( "y = 51.5/3.5
\n" ); document.write( "y = 14.7 km is the yellow trail
\n" ); document.write( ":
\n" ); document.write( "r = 2(14.7) - 10
\n" ); document.write( "r = 19.4 km is the red trail
\n" ); document.write( ":
\n" ); document.write( "b = .5(14.7) - 1.5
\n" ); document.write( "b = 5.85 km is the blue trail
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "See if they add up
\n" ); document.write( "14.7 + 19.4 + 5.85 = 39.95 close enough\r
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