document.write( "Question 312076: Ride the peaks. Smith bicycled 45 miles going east from
\n" ); document.write( "Durango, and Jones bicycled 70 miles. Jones averaged
\n" ); document.write( "5 miles per hour more than Smith, and his trip took one-half
\n" ); document.write( "hour longer than Smith’s. How fast was each one traveling?
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Algebra.Com's Answer #223309 by ankor@dixie-net.com(22740)\"\" \"About 
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Smith bicycled 45 miles going east from Durango, and Jones bicycled 70 miles.
\n" ); document.write( " Jones averaged 5 miles per hour more than Smith, and his trip took one-half
\n" ); document.write( "hour longer than Smith’s.
\n" ); document.write( " How fast was each one traveling?
\n" ); document.write( ":
\n" ); document.write( "Let s = Smith's speed
\n" ); document.write( "then
\n" ); document.write( "(s+5) = Jone's speed
\n" ); document.write( ":
\n" ); document.write( "Write a time equation, Time = dist/speed
\n" ); document.write( ":
\n" ); document.write( "Jones time - Smiths time = .5 hr
\n" ); document.write( "\"70%2F%28%28s%2B5%29%29\" - \"45%2Fs\" = .5
\n" ); document.write( "multiply by s(s+5), results:
\n" ); document.write( "70s - 45(s+5) = .5s(s+5)
\n" ); document.write( ":
\n" ); document.write( "70s - 45s - 225 = .5s^2 + 2.5s
\n" ); document.write( "25s - 225 = .5s^2 + 2.5s
\n" ); document.write( "combine on the right
\n" ); document.write( "0 = .5s^2 + 2.5s - 25s + 225
\n" ); document.write( "A quadratic equation
\n" ); document.write( ".5s^2 - 22.5s + 225 = 0
\n" ); document.write( "Get rid of th decimals, mult by 2
\n" ); document.write( "s^2 - 45s + 450 = 0
\n" ); document.write( "Factors to
\n" ); document.write( "(s-15)(s-30) = 0
\n" ); document.write( "Two solutions
\n" ); document.write( "s = 15 mph is Smith's time, then Jones time = 20 mph
\n" ); document.write( "and
\n" ); document.write( "s = 30 mph is Smith's time, then Jones time = 35
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\n" ); document.write( "The slower time would make more sense for bicycle
\n" ); document.write( "Check by finding the times
\n" ); document.write( "70/20 = 3.5
\n" ); document.write( "45/15 = 3.0
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\n" ); document.write( "differ: .5h
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