document.write( "Question 139174: Please help me translate into a quadratic equation and solve.\r
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document.write( "Steve traveled 200 miles at a certain speed. Had he gone 10 MPH faster, the trip would have taken 1 hour less. Find the speed of his vehicle. \n" );
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Algebra.Com's Answer #101502 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! Steve traveled 200 miles at a certain speed. Had he gone 10 MPH faster, the trip would have taken 1 hour less. Find the speed of his vehicle. \n" ); document.write( ": \n" ); document.write( "Let s = his actual speed \n" ); document.write( "then \n" ); document.write( "(s+10) = his \"if\" speed \n" ); document.write( ": \n" ); document.write( "Write a time equation: Time = dist/speed \n" ); document.write( ": \n" ); document.write( "Actual time = Faster speed time + 1 hr \n" ); document.write( " \n" ); document.write( "Multiply equation by s(s+10) to get rid of the denominators: \n" ); document.write( "s(s+10)* \n" ); document.write( "cancel the denominators out and you have: \n" ); document.write( "200(s+10) = 200s + s(s+10) \n" ); document.write( ": \n" ); document.write( "200s + 2000 = 200s + s^2 + 10s \n" ); document.write( ": \n" ); document.write( "Combine; \n" ); document.write( "0 = s^2 + 10s + 200s - 200s - 2000 \n" ); document.write( "A quadratic equation \n" ); document.write( "s^2 + 10s - 2000 = 0 \n" ); document.write( "Factors to: \n" ); document.write( "(s+50) (s-40) = 0 \n" ); document.write( "The positive solution: \n" ); document.write( "s = +40 mph is his speed \n" ); document.write( ": \n" ); document.write( "Check solution by finding the times \n" ); document.write( "200/40 = 5 hrs \n" ); document.write( "200/50 = 4 hrs \n" ); document.write( " |