document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=980173>Question 980173</A>: <I><SPAN STYLE=\"word-break: break-all;\"> There was a question about an army travelling 5 mph and a messenger on horseback travelling  at 10 mph(question asks for the distance from front to rear) that was answered by ankor@dixie.net that I didn't really understand why did he add and subtract 5 to the 10 mph rate. I know that you do add +-r or a given amount in wind and water current problems. Is that why you added and subtracted the 5? Some logic of why is all I need, so that I can understand a problem that I've never seen before in any other place than the Schaum College Algebra textbook. Please help. QUESTION: WHY WAS THE 5 ADDED AND SUBTRACTED FROM 10 TO GET 15 AND 5(Denominators) AND WHY 5 AND NOT R? Anybody that understands fully why and can explain is welcome. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #601378 by </B><A HREF=/tutors/aboutme.mpl?userid=josmiceli><B>josmiceli(19441)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josmiceli><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=josmiceli><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=601378\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The moving army is the exact opposite of the<BR>\n" );
document.write( "current in a stream because the motion of the<BR>\n" );
document.write( "army has ZERO effect on the messenger's<BR>\n" );
document.write( "motion.<BR>\n" );
document.write( "If you are moving in the same direction as the army<BR>\n" );
document.write( "at 10 mi/hr and the army is moving at 1 mi/hr<BR>\n" );
document.write( "you can imagine the army is stopped and you are<BR>\n" );
document.write( "moving at <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+10+-+1+=+9+ ALIGN=MIDDLE  ALT=\"+10+-+1+=+9+\"   DISABLED_style= \"max-width:90%; height:auto;\" > mi/hr<BR>\n" );
document.write( "If the army was a stream moving in the same<BR>\n" );
document.write( "direction, the current would ADD to the<BR>\n" );
document.write( "messenger's motion<BR>\n" );
document.write( "--------------------------------<BR>\n" );
document.write( "If you are moving opposite to the direction of the army,<BR>\n" );
document.write( "imagine that the army is stopped, and you are moving<BR>\n" );
document.write( "at the sum = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+10+%2B+1+ ALIGN=MIDDLE  ALT=\"+10+%2B+1+\"   DISABLED_style= \"max-width:90%; height:auto;\" > mi/hr<BR>\n" );
document.write( "------------------------------<BR>\n" );
document.write( "Just think about the current of a stream having a direct<BR>\n" );
document.write( "effect on a boat ( adding or subtracting ) <BR>\n" );
document.write( "Think about the army as the background against which <BR>\n" );
document.write( "you are moving either whizzing  by you making it easy<BR>\n" );
document.write( "to get where you are going, or the background is moving<BR>\n" );
document.write( "away from you making it harder to get where you're going<BR>\n" );
document.write( "Hope this helps<BR>\n" );
document.write( "  </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );