document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=368684>Question 368684</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Car speed. On a sales trip, Mark drives the 600 mi to Richmond averaging a certain speed. The return trip is made at an average speed that is 10 mph slower. Total time for the round trip is 22 hr. Find Mark’s average speed on each part of the trip. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #262691 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=262691\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  Car speed. On a sales trip, Mark drives the 600 mi to Richmond averaging a certain speed. The return trip is made at an average speed that is 10 mph slower. Total time for the round trip is 22 hr. Find Mark’s average speed on each part of the trip.<BR>\n" );
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document.write( "To Richmond DATA:<BR>\n" );
document.write( "distance = 600 miles ; rate = x mph ; time = 600/x hrs<BR>\n" );
document.write( "-----------------------<BR>\n" );
document.write( "From Richmond DATA:<BR>\n" );
document.write( "distance = 600 miles ; rate = x-10 mph ; time = 600/(x-10) hrs.<BR>\n" );
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document.write( "Equation:<BR>\n" );
document.write( "time + time = 22 hrs<BR>\n" );
document.write( "600/x + 600/(x-10) = 22<BR>\n" );
document.write( "----<BR>\n" );
document.write( "600(x-10) + 600x = 22x(x-10)<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "1200x - 6000 = 22x^2-220x<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "22x^2 - 1420x + 6000 = 0<BR>\n" );
document.write( "11x^2 - 710x + 3000 = 0<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "Positive solution:<BR>\n" );
document.write( "x = 60 mph (rate to Richmond)<BR>\n" );
document.write( "x-10 = 50 mph (rate from Richmond)<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );