document.write( "Question 239415: A biker completed a trip from town A to town B. If he rode 3 km per hour faster, then he could spend one hour less for this trip. If he rode 2 km per hour slower, he would be one hour late.
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document.write( "Find the distance between towns, speed of the biker, and time of traveling.
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Algebra.Com's Answer #175836 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! A biker completed a trip from town A to town B. \n" ); document.write( " If he rode 3 km per hour faster, then he could spend one hour less for this trip. \n" ); document.write( "If he rode 2 km per hour slower, he would be one hour late.\r \n" ); document.write( "\n" ); document.write( "Find the distance between towns, speed of the biker, and time of traveling. \n" ); document.write( ": \n" ); document.write( "Let s = the biker's speed \n" ); document.write( "then \n" ); document.write( "(s+3) = 3 km faster speed \n" ); document.write( "and \n" ); document.write( "(s-2) = 2 km slower speed \n" ); document.write( ": \n" ); document.write( "Let d = dist from a to b \n" ); document.write( ": \n" ); document.write( "Write two time equations: time = dist/speed \n" ); document.write( " \n" ); document.write( "and \n" ); document.write( " \n" ); document.write( ": \n" ); document.write( "Both equations = 1, so we can write it: \n" ); document.write( " \n" ); document.write( "simplify, divide each term by d \n" ); document.write( " \n" ); document.write( "combine like terms \n" ); document.write( " \n" ); document.write( ": \n" ); document.write( " \n" ); document.write( ": \n" ); document.write( "Multiply by s(s+3)(s-2) to get rid of the denominators: \n" ); document.write( "2(s+3)(s-2) - s(s-2) = s(s+3) \n" ); document.write( ": \n" ); document.write( "2(s^2 + s - 6) - s^2 + 2s = s^2 + 3s \n" ); document.write( ": \n" ); document.write( "2s^2 + 2s - 12 - s^2 + 2s = s^2 + 3s \n" ); document.write( "Combine like terms on the left \n" ); document.write( "2s^2 - s^2 - s^2 + 2s + 2s - 3s - 12 = 0 \n" ); document.write( ": \n" ); document.write( "s - 12 = 0 \n" ); document.write( "s = 12 km/hr is the speed \n" ); document.write( ": \n" ); document.write( "Find the dist between towns using \n" ); document.write( " \n" ); document.write( ": \n" ); document.write( " \n" ); document.write( "Multiply by 60 \n" ); document.write( "5d - 4d = 60 \n" ); document.write( "d = 60 km is the distance \n" ); document.write( ": \n" ); document.write( "Find the time: \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "Check solutions in: \n" ); document.write( " \n" ); document.write( ": \n" ); document.write( " \n" ); document.write( "6 - 5 = 1 hr \n" ); document.write( " \n" ); document.write( " |