document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=910302>Question 910302</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The total travel time for a family to reach a campsite is 2 hours. They drive 81 miles and hike 2 miles. <BR>\n" );
document.write( "If they drive 50 mph faster than they hike, what is their average driving speed?<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #552382 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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/cgi-bin/show-face.mpl?user=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=552382\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The total travel time for a family to reach a campsite is 2 hours. They drive 81 miles and hike 2 miles. <BR>\n" );
document.write( "If they drive 50 mph faster than they hike, what is their average driving speed?<BR>\n" );
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document.write( "d = r*t<BR>\n" );
document.write( "t = d/r<BR>\n" );
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document.write( "r = hiking speed<BR>\n" );
document.write( "2/r + 81/(r+50) = 2<BR>\n" );
document.write( "2(r+50) + 81r = 2r*(r+50) = 2r^2 + 100r<BR>\n" );
document.write( "2r + 100 + 81r = 2r^2 + 100r<BR>\n" );
document.write( "2r^2 + 17r - 100 = 0<BR>\n" );
document.write( "(r - 4)*(2r + 25) = 0 (Ignore the negative solution)<BR>\n" );
document.write( "r = 4 mi/hr<BR>\n" );
document.write( "Driving speed = 54 mi/hr </SPAN>\n" );
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