document.write( "Question 130883: During the first part of a trip, a canoeist travels 75 miles at a certain speed. The canoeist travels 24 miles on the second part of the trip at a speed 5 mph slower. The total time for the trip is 5 hours. What was the speed on each part of the trip?\r
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document.write( "The speed on the first part of the trip was ____ mph.\r
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document.write( "The speed on the second part of the trip was ____ mph.\r
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Algebra.Com's Answer #95740 by ptaylor(2198)![]() ![]() You can put this solution on YOUR website! Distance(d)=Rate(r) times Time(t) or d=rt; r=d/t and t=d/r\r \n" ); document.write( "\n" ); document.write( "Let r=speed for first part of trip \n" ); document.write( "Then r-5=speed on second part of trip\r \n" ); document.write( "\n" ); document.write( "Time required for first part of trip= d/r=75/r \n" ); document.write( "Time required for second part of trip=d/r=24/(r-5)\r \n" ); document.write( "\n" ); document.write( "Now we are told that the sum of the above two times equals 5 hours, so:\r \n" ); document.write( "\n" ); document.write( "75/r+24/(r-5)=5 multiply each term by r(r-5)\r \n" ); document.write( "\n" ); document.write( "75(r-5)+24r=5r(r-5) get rid of parens\r \n" ); document.write( "\n" ); document.write( "75r-375+24r=5r^2-25r subtract 5r^2 from and add 25r to both sides \n" ); document.write( "75r-375+24r-5r^2+25r=5r^2-5r^2-25r+25r collect like terms\r \n" ); document.write( "\n" ); document.write( "-5r^2+124r-375=0 multiply each term by -1\r \n" ); document.write( "\n" ); document.write( "5r^2-124r+375=0 quadratic in standard form. Solve using quadratic formula \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "r-5=3.535-5=NEGATIVE VALUE NO GOOD!!!!\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "CK\r \n" ); document.write( "\n" ); document.write( "75/21.275 + 24/16.275=5 \n" ); document.write( "3.525+1.474=5 \n" ); document.write( "4.999999--~~~~5\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Hope this helps---ptaylor\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |