document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=571707>Question 571707</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Please help! I really need to learn how to do travel word problems and they confuse me so much. \r<BR>\n" );
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document.write( "The speed of a river's current is 4 miles per hour. You travel 2 miles with the current and then return to where you started in a total time of 1.25 hours. What is your speed in the still water in 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 #368181 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=368181\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The speed of a river's current is 4 miles per hour.<BR>\n" );
document.write( " You travel 2 miles with the current and then return to where you started in a total time of 1.25 hours.<BR>\n" );
document.write( " What is your speed in the still water in miles per hour?<BR>\n" );
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document.write( "let s = the speed of your boat in still water<BR>\n" );
document.write( "then<BR>\n" );
document.write( "(s-4) = your effective speed up-stream<BR>\n" );
document.write( "and<BR>\n" );
document.write( "(s+4) = your effective speed down-stream<BR>\n" );
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document.write( "Write a time equation; time = dist/speed<BR>\n" );
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document.write( "Time upstr + time downstr = 1.25 hrs<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2%2F%28%28s-4%29%29 ALIGN=MIDDLE  ALT=\"2%2F%28%28s-4%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2%2F%28%28s%2B4%29%29 ALIGN=MIDDLE  ALT=\"2%2F%28%28s%2B4%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 1.25<BR>\n" );
document.write( "Multiply by (s-4)(s+4)<BR>\n" );
document.write( "(s+4)*s-4)<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2%2F%28%28s-4%29%29 ALIGN=MIDDLE  ALT=\"2%2F%28%28s-4%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > + (s+4)(s-4*<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2%2F%28%28s%2B4%29%29 ALIGN=MIDDLE  ALT=\"2%2F%28%28s%2B4%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 1.25(s+4)(s-4)<BR>\n" );
document.write( "Cancel the denominators, and you have<BR>\n" );
document.write( "2(s+4) + 2(s-4) = 1.25(s^2-16)<BR>\n" );
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document.write( "2s + 8 + 2s - 8 = 1.25s^2 - 20<BR>\n" );
document.write( "Combine to form a quadratic equation<BR>\n" );
document.write( "0 = 1.25s^2 - 4s - 20<BR>\n" );
document.write( "You have to use the quadratic equation to find s<BR>\n" );
document.write( "only on solution will make sense, I got <BR>\n" );
document.write( "5.91 mph is his approx speed in still water  </SPAN>\n" );
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