document.write( "Question 948114: To travel 110 miles, it takes Sue, riding a moped, 3 hours less time than it takes Doreen to travel 72 miles riding a bicycle. Sue travels 13 miles per hour faster than Doreen. Find the times and rates of both girls. \n" ); document.write( "
Algebra.Com's Answer #578640 by stanbon(75887)![]() ![]() ![]() You can put this solution on YOUR website! To travel 110 miles, it takes Sue, riding a moped, 3 hours less time than it takes Doreen to travel 72 miles riding a bicycle. Sue travels 13 miles per hour faster than Doreen. Find the times and rates of both girls. \n" ); document.write( "-------------------- \n" ); document.write( "Doreen DATA: \n" ); document.write( "dist = 72 miles ; time = x hrs ; rate = d/t = 72/x mph \n" ); document.write( "-------------------- \n" ); document.write( "Sue DATA: \n" ); document.write( "dist = 110 miles ; time = x-3 hrs ; rate = d/t = 110/(x-3) mph \n" ); document.write( "======= \n" ); document.write( "Equation:: \n" ); document.write( "Sue = Doreen + 13 \n" ); document.write( "110/(x-3) = [72/x] + 13 \n" ); document.write( "--------------------------- \n" ); document.write( "110x = 72(x-3) + 13x(x-3) \n" ); document.write( "110x = 72x - 216 + 13x^2 - 39x \n" ); document.write( "------- \n" ); document.write( "38x = -216 + 13x^2 - 39x \n" ); document.write( "----- \n" ); document.write( "13x^2 -77x -216 = 0 \n" ); document.write( "Positive solution:: \n" ); document.write( "x = 8 \n" ); document.write( "Doreen rate = 72/8 = 9 mph \n" ); document.write( "Sue rate = 110/(8-3) = 22 mph \n" ); document.write( "----- \n" ); document.write( "Cheers, \n" ); document.write( "Stan H. \n" ); document.write( "--------- \n" ); document.write( " |