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You can put this solution on YOUR website!
During the first part of a canoe trip, Tim covered 60 km at a certain speed.
\n" ); document.write( "He then traveled 24 km at a speed that was 4 km/h slower.
\n" ); document.write( "If the total time for the trip was 8 hr, what was the speed on each part of the trip?
\n" ); document.write( "--------------
\n" ); document.write( "1st part DATA:
\n" ); document.write( "distance = 60 km ; rate = x km/h ; time = d/r = 60/x hrs
\n" ); document.write( "---
\n" ); document.write( "2nd part DATA:
\n" ); document.write( "distance = 24 km ; rate = x-4 km/h ; time = d/r = 24/(x-4) hrs
\n" ); document.write( "-------------------
\n" ); document.write( "Equation
\n" ); document.write( "time + time = 8 hrs
\n" ); document.write( "60/x + 24(x-4) = 8
\n" ); document.write( "Multiply thru by x(x-4) to get:
\n" ); document.write( "60(x-4) + 24x = 8x(x-4)
\n" ); document.write( "15(x-4) + 6x = 2x(x-4)
\n" ); document.write( "15x-60 + 6x = 2x^2-8x
\n" ); document.write( "2x^2 - 29x + 60 = 0
\n" ); document.write( "x = [29 +- sqrt(29^2 - 4*2*60)]/4
\n" ); document.write( "x = [29 +- sqrt(361)]/4
\n" ); document.write( "x = [29 +- 19]/4
\n" ); document.write( "x = 12 or x = 5/2
\n" ); document.write( "---
\n" ); document.write( "solution that gives positive results:
\n" ); document.write( "x = 12 km/h (speed on the 1st part)
\n" ); document.write( "x -4 = 8 km/h (speed on the 2nd part)
\n" ); document.write( "========================================
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H. \n" ); document.write( "