document.write( "Question 853754: a man drove at a constant speed from his city 180 miles away. On the return trip, he increased his constant speed by 5 mph and made the return trip in 24 minutes less time than had been required to drive to the city. What was his sped from home to the city? \n" ); document.write( "
Algebra.Com's Answer #514223 by mananth(16946)![]() ![]() You can put this solution on YOUR website! Time taken in forward journey = 180/x \n" ); document.write( "x is the speed\r \n" ); document.write( "\n" ); document.write( "return journey speed increased by 5 mph. (x+5)\r \n" ); document.write( "\n" ); document.write( "Time forward - time return = 24/60 = 2/5 hours\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Take LCM of denominator \n" ); document.write( "5x(x+5)\r \n" ); document.write( "\n" ); document.write( "180*5*(x+5) -180*5*x=2*x*(x+5)\r \n" ); document.write( "\n" ); document.write( "900x+4500-900x=2x^2+10x\r \n" ); document.write( "\n" ); document.write( "2x^2+10x-4500=0 \n" ); document.write( "/2 \n" ); document.write( "x^2+5x-2250=0\r \n" ); document.write( "\n" ); document.write( "x^2+50x-45x-2250=0\r \n" ); document.write( "\n" ); document.write( "x(x+50)-45(x+50)=0\r \n" ); document.write( "\n" ); document.write( "(x+50)(x-45)=0 \n" ); document.write( "x= -50 OR 45\r \n" ); document.write( "\n" ); document.write( "Speed from home was 45 mph\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |