document.write( "Question 167344: On a round trip of 350 miles in each direction, Joseph averaged 10mph more returning than he did going. If the return trip took 4 hours less time, find the time for each direction. \n" ); document.write( "

Algebra.Com's Answer #123240 by Mathtut(3670) $\"\"$ $\"About$

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d=r*t\r
\n" ); document.write( "\n" ); document.write( "distance going =distance returning=350
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\n" ); document.write( "so r*t going = r*t returning
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\n" ); document.write( "rt=(r+10)(t-4)
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\n" ); document.write( "rt=rt-4r+10t-40-----> we have -4r+10t-40=0 since t=350/r
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\n" ); document.write( "we have -4r+10(350/r)-40=0
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\n" ); document.write( "-4r+(3500/r)-40=0---->mult by r---> $\"-4r%5E2%2B3500-40r=0\"$ $\"4r%5E2%2B40r-3500=0\"$
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\n" ); document.write( "quadratic formula yields 25 and -35...we throw out the negative value
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\n" ); document.write( "r=25 going
\n" ); document.write( "r+10=35 returning
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\n" ); document.write( "time going $\"highlight%28350%2F25=14%29\"$ hours
\n" ); document.write( "time returning $\"highlight%2814-4=10%29\"$ hours\r
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