document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1174986>Question 1174986</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Serge’s outgoing 115-kilometer bike involved riding uphill for 2 hours and on level ground for 3<BR>\n" );
document.write( "hours. On the return trip, on a different 135-kilometer trail, he rode downhill for 2 hours and on<BR>\n" );
document.write( "level ground for 3 hours. Determine Serge’s three speeds if his speed on level ground is the<BR>\n" );
document.write( "average of his uphill and downhill speeds. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #800501 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13200)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=greenestamps><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=greenestamps><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=800501\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "Given that his speed on level ground is the average of his uphill and downhill speeds, let the three speeds be<br><BR>\n" );
document.write( "x+y downhill<BR>\n" );
document.write( "x on level ground<BR>\n" );
document.write( "x-y uphill<br><BR>\n" );
document.write( "2 hours uphill and 3 hours on level ground covered 115 km:<BR>\n" );
document.write( "2(x-y)+3(x) = 115<br><BR>\n" );
document.write( "2 hours downhill and 3 hours on level ground covered 135 km:<BR>\n" );
document.write( "2(x+y)+3(x) = 135<br><BR>\n" );
document.write( "Solve the pair of equations using basic algebra.<br><BR>\n" );
document.write( "2x-2y+3x = 115<BR>\n" );
document.write( "5x-2y = 115<br><BR>\n" );
document.write( "2x+2y+3x = 135<BR>\n" );
document.write( "5x+2y = 135<br><BR>\n" );
document.write( "Comparing the two equations (i.e., subtracting one from the other)....<br><BR>\n" );
document.write( "4x = 20<BR>\n" );
document.write( "x = 5<br><BR>\n" );
document.write( "Plug x=5 into one of the equations to solve for y; then use your x and y values to find the three speeds.<br><BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );