document.write( "Question 452380: A man rode a bicycle for 12 miles and then hiked an additional 8 miles. The total time for the trip
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document.write( "was 5 hours. If his rate when he was riding a bicycle was 10 miles per hour faster than his rate
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document.write( "walking, what was each rate? \n" );
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Algebra.Com's Answer #310982 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! A man rode a bicycle for 12 miles and then hiked an additional 8 miles. \n" ); document.write( " The total time for the trip was 5 hours. \n" ); document.write( " If his rate when he was riding a bicycle was 10 miles per hour faster than his rate walking, what was each rate? \n" ); document.write( ": \n" ); document.write( "Let s = his walking rate \n" ); document.write( "then \n" ); document.write( "(s+10) = his biking rate \n" ); document.write( ": \n" ); document.write( "Write a time equation; time = dist/speed \n" ); document.write( ": \n" ); document.write( "walk time + biking time = 5 hrs \n" ); document.write( " \n" ); document.write( ": \n" ); document.write( "Multiply by s(s+10) \n" ); document.write( "8(s+10) + 12s = 5s(s+10) \n" ); document.write( "8s + 80 + 12s = 5s^2 + 50s \n" ); document.write( "20s + 80 = 5s^2 + 50s \n" ); document.write( "0 = 5s^2 + 50s - 20s - 80 \n" ); document.write( ": \n" ); document.write( "A quadratic equation \n" ); document.write( "5s^2 + 30s - 80 = 0 \n" ); document.write( ": \n" ); document.write( "Simplify, divide by 5 \n" ); document.write( "s^2 + 6s - 16 = 0 \n" ); document.write( ": \n" ); document.write( "factors to \n" ); document.write( "(s+8)(s-2) = 0 \n" ); document.write( ": \n" ); document.write( "the positive solution is all we want here \n" ); document.write( "s = 2 mph walking speed \n" ); document.write( "then, obviously: \n" ); document.write( "12 mph biking speed \n" ); document.write( "; \n" ); document.write( ": \n" ); document.write( "Check that in the time equation \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " |