document.write( "Question 761492: To travel 154 miles, it takes Sue, riding a moped, 3 hours less time than it takes Doreen to travel 70 miles riding a bicycle. Sue travels 15 miles per hour faster than Doreen. Find the times and rates of both girls. \n" ); document.write( "
Algebra.Com's Answer #463252 by stanbon(75887)![]() ![]() ![]() You can put this solution on YOUR website! To travel 154 miles, it takes Sue, riding a moped, 3 hours less time than it takes Doreen to travel 70 miles riding a bicycle. Sue travels 15 miles per hour faster than Doreen. Find the times and rates of both girls. \n" ); document.write( "--------------- \n" ); document.write( "Sue DATA: \n" ); document.write( "distance = 154 miles ; time = x-3 hrs ; rate = d/t = 154/(x-3) mph \n" ); document.write( "------------------ \n" ); document.write( "Doreen DATA: \n" ); document.write( "distance = 70 miles ; time = x hrs ; rate = 70/x mph \n" ); document.write( "------------------ \n" ); document.write( "Equation: \n" ); document.write( "rate - rate = 15 mph \n" ); document.write( "154/(x-3) - 70/x = 15 \n" ); document.write( "154x - 70(x-3)=15x(x-3) \n" ); document.write( "---------------------------- \n" ); document.write( "154x - 70x + 210 = 15x^2 - 15x \n" ); document.write( "84x + 210 = 15x^2 - 15x \n" ); document.write( "----- \n" ); document.write( "15x^2 - 99x - 210 = 0 \n" ); document.write( "5x^2 - 33x - 70 = 0 \n" ); document.write( "---------------- \n" ); document.write( "Positive solution: \n" ); document.write( "x = 8.89 hrs (Doreen time) ; 70/8.289 = 8.445 mph (Doreen rate) \n" ); document.write( "---- \n" ); document.write( "x-3 = 5.89 hrs (Sue time) ; 154/5.89 = 18.24 mph (Sue rate) \n" ); document.write( "=================== \n" ); document.write( "Cheers, \n" ); document.write( "Stan H. \n" ); document.write( "=================== \n" ); document.write( " |