document.write( "Question 1074943: A bicyclist rides his bicycle 20 miles up a hill and then comes back down. His speed coming downhill is 12 miles per hour faster than going uphill. The round trip takes 2 hours and 30 minutes (=5/2 hours). What was the speed of the bicyclist going uphill? \n" ); document.write( "

Algebra.Com's Answer #689616 by jorel1380(3719) $\"\"$ $\"About$

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Let n be the speed of the cyclist going up hill. Then his speed downhill would be n+12. So:
\n" ); document.write( "20/n + 20/n+12=5/2
\n" ); document.write( "40/n + 40/n+12=5
\n" ); document.write( "40(n+12)+40n=5n²+60n
\n" ); document.write( "5n²-20n-480=0
\n" ); document.write( "n²-4n-96=0
\n" ); document.write( "(n-12)(n+8)=0
\n" ); document.write( "n=12 or -8
\n" ); document.write( "The uphill speed of the cyclist was 12 mph. ☺☺☺☺ \n" ); document.write( "

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