document.write( "Question 1048489: A bus traveled on a straight road for 2 h at an average speed that was 20 mph faster than its average speed on a winding road. The time spent on the winding road was 3 h. Find the average speed on the winding road if the total trip was 250 mi. \n" ); document.write( "

Algebra.Com's Answer #664079 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"+d+\"$ = distance in miles traveled on
\n" ); document.write( "the straight road
\n" ); document.write( " $\"+250+-+d+\"$ = distance in miles traveled on the
\n" ); document.write( "winding road
\n" ); document.write( "Let $\"+s+\"$ = speed in mi/hr on winding road
\n" ); document.write( " $\"+s+%2B+20+\"$ = speed in mi/hr on straight road
\n" ); document.write( "-------------------------------------------
\n" ); document.write( "Equation for straight road:
\n" ); document.write( "(1) $\"+d+=+%28+s%2B20+%29%2A2+\"$
\n" ); document.write( "Equation for winding road:
\n" ); document.write( "(2) $\"+250+-+d+=+s%2A3+\"$
\n" ); document.write( "--------------------------
\n" ); document.write( "Substitute (1) into (2)
\n" ); document.write( "(2) $\"+250+-+2s+-+40+=+s%2A3+\"$
\n" ); document.write( "(2) $\"+5s+=+210+\"$
\n" ); document.write( "(2) $\"+s+=+42+\"$
\n" ); document.write( "The speed on the winding road was 42 mi/hr
\n" ); document.write( "-----------------
\n" ); document.write( "check:
\n" ); document.write( "(1) $\"+d+=+%28+42+%2B+20+%29%2A2+\"$
\n" ); document.write( "(1) $\"+d+=+124+\"$ mi
\n" ); document.write( "and
\n" ); document.write( "(2) $\"+250+-+d+=+3%2A42+\"$
\n" ); document.write( "(2) $\"+d+=+250+-+126+\"$
\n" ); document.write( "(2) $\"+d+=+124+\"$ mi
\n" ); document.write( "OK
\n" ); document.write( " \n" ); document.write( "

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