document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1103088>Question 1103088</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Sam was driving to Chicago. His rate for the first 80 miles was 10 mph faster than his rate for the last 140 miles. If his entire trip took 4 hours, what was his speed on each part of the trip? Round your answer to the nearest miles per hour </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #717771 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=717771\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Sam was driving to Chicago. His rate for the first 80 miles was 10 mph faster than his rate for the last 140 miles. If his entire trip took 4 hours, what was his speed on each part of the trip? Round your answer to the nearest miles per hour<BR>\n" );
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document.write( "First 80 mile DATA:<BR>\n" );
document.write( "dist = 80 miles ; rate = r+10 mph ; time = 80/(r+10) hrs<BR>\n" );
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document.write( "Last 140 miles DATA:<BR>\n" );
document.write( "dist = 140 miles ; rate = r mph ; time = 140/r hrs.<BR>\n" );
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document.write( "Equation:<BR>\n" );
document.write( "time + time = 4 hrs.<BR>\n" );
document.write( "80/(r+10) + 140/r = 4 hrs <BR>\n" );
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document.write( "80r + 140r + 1400 = 4r(r+10)<BR>\n" );
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document.write( "20r + 35r + 350 = r^2+10r<BR>\n" );
document.write( "r^2 - 45r - 350 = 0<BR>\n" );
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document.write( "r = 51.76 mph<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" );