document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1049036>Question 1049036</A>: <I><SPAN STYLE=\"word-break: break-all;\"> You drive from Phoenix to Santa Fe, a distance of 480 miles. A week later you return using the same route.  On the way back to Phoenix your average speed is 5 miles per hour faster. This made a 25-minute difference in time. Find the average speed for the trip there and the average speed for the trip back. Find the total time it took to drive there and the total time it took to drive back. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #664585 by </B><A HREF=/tutors/aboutme.mpl?userid=jorel555><B>jorel555(1290)</B></A><img src=\"/images/stars/stars-12.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jorel555><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=664585\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let r represent your speed in mph. 25/60=5/12 hour. So:<BR>\n" );
document.write( "480/r=480/(r+5)+5/12 hr<BR>\n" );
document.write( "5760/r=5760/(r+5)+5<BR>\n" );
document.write( "5760(r+5)=5760r+5(rē+5r)<BR>\n" );
document.write( "5760r+28800=5760r+25r+5rē<BR>\n" );
document.write( "5rē+25r-28800=0<BR>\n" );
document.write( "rē+5r-5760=0<BR>\n" );
document.write( "Using the quadratic formula; we get r=73.436, and -78.436. Throwing out the negative result, we get the average speed going there as 73.436 mph; going back the average speed was 78.436.<BR>\n" );
document.write( "Total drive time there:480/73.436=6.54 hours<BR>\n" );
document.write( "Total drive time back:480/78.436=6.12 hours<BR>\n" );
document.write( " </SPAN>\n" );
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