document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=655526>Question 655526</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I really need help.\r<BR>\n" );
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document.write( "A tugboat goes 140miles upstream in 10 hours. The return trip downstream takes 5 hours. Find the speed.<BR>\n" );
document.write( "the speed pf the tugboat is ___mph, and the speed of the current is ___mph. \r<BR>\n" );
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document.write( "this is substitution to solve linear equations. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #409169 by </B><A HREF=/tutors/aboutme.mpl?userid=MathTherapy><B>MathTherapy(10552)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=MathTherapy><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=MathTherapy><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=409169\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <BR>\n" );
document.write( "I really need help.\r<BR>\n" );
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document.write( "A tugboat goes 140miles upstream in 10 hours. The return trip downstream takes 5 hours. Find the speed.<BR>\n" );
document.write( "the speed pf the tugboat is ___mph, and the speed of the current is ___mph. \r<BR>\n" );
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document.write( "this is substitution to solve linear equations.\r<BR>\n" );
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document.write( "Let the speed of the boat, in still water be S, and the the speed of the current, C\r<BR>\n" );
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document.write( "In going 140 miles in 10 hours, the boat's speed, against the current = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=140%2F10 ALIGN=MIDDLE  ALT=\"140%2F10\"   DISABLED_style= \"max-width:90%; height:auto;\" >, or 14 mph. This means that S - C = 14<BR>\n" );
document.write( "C = S - 14 ----- eq (i)\r<BR>\n" );
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document.write( "In going 140 miles in 5 hours, the boat's speed, with the current = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=140%2F5 ALIGN=MIDDLE  ALT=\"140%2F5\"   DISABLED_style= \"max-width:90%; height:auto;\" >, or 28 mph. This means that S + C = 28 ----- eq (ii)\r<BR>\n" );
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document.write( "S + S - 14 = 28 ----- Substituting S - 14 for C in eq (ii)\r<BR>\n" );
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document.write( "2S = 28 + 14\r<BR>\n" );
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document.write( "2S = 42\r<BR>\n" );
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document.write( "S, or speed of boat in still water = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=42%2F2 ALIGN=MIDDLE  ALT=\"42%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" >, or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight_green%2821%29 ALIGN=MIDDLE  ALT=\"highlight_green%2821%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > mph\r<BR>\n" );
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document.write( "C = 21 - 14 ------ Substituting 21 for S in eq (i)\r<BR>\n" );
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document.write( "C, or speed of current = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight_green%287%29 ALIGN=MIDDLE  ALT=\"highlight_green%287%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > mph\r<BR>\n" );
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document.write( "You can do the check!!!\r<BR>\n" );
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document.write( "Send comments and “thank-yous” to “D” at MathMadEzy@aol.com  </SPAN>\n" );
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