document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=558130>Question 558130</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A passenger plane flew to moscow and back. The trip there took five hours and the trip back took nine hours.  It averaged 144 km/h faster on the trip there than on the return trip.  Find the passenger plane's average speed on the outbound trip.\r<BR>\n" );
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document.write( "O.k so I did have a go at it Trying to use a system of equations using the substitution method to eliminate one unknown but it didn't work.  I will try and explain what I was playing around with:\r<BR>\n" );
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document.write( "D1 = Distance there  D2 = Distance back ( but not sure if I needed this as it is same Distance )<BR>\n" );
document.write( "Average Speed = S  \r<BR>\n" );
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document.write( "D1/5 + D2/9 = S\r<BR>\n" );
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document.write( "D1/5 = D2/9+144 ( I tried substituting this in )\r<BR>\n" );
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document.write( "D2/9+144 + D2/9 = S ( then I combined the like terms )\r<BR>\n" );
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document.write( "D2/18+144 = s ( but this is where I realized I had failed as I still had 2 variables.\r<BR>\n" );
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document.write( "Please help me someone I am so bad at word problems and I would love to be confident at them. \r<BR>\n" );
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document.write( "P.S I wasn't sure about which was the outbound trip, I guessed it meant the trip back.\r<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 #852289 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13203)</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=852289\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "NOTE:<BR>\n" );
document.write( "Outbound <---> going<BR>\n" );
document.write( "Inbound <---> returning<br><BR>\n" );
document.write( "Let x be the lower speed (on the return trip, which took longer)<BR>\n" );
document.write( "Then x+144 is the outbound speed<br><BR>\n" );
document.write( "The distances (rate times time) are the same:<br><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=9%28x%29=5%28x%2B144%29 ALIGN=MIDDLE  ALT=\"9%28x%29=5%28x%2B144%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=9x=5x%2B720 ALIGN=MIDDLE  ALT=\"9x=5x%2B720\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=4x=720 ALIGN=MIDDLE  ALT=\"4x=720\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=180 ALIGN=MIDDLE  ALT=\"x=180\"   DISABLED_style= \"max-width:90%; height:auto;\" ><br><BR>\n" );
document.write( "The speed on the return trip was x=180 km/hr; the speed on the outbound trip was x+144 = 324 km/hr.<br><BR>\n" );
document.write( "ANSWER: 324 km/hr<br><BR>\n" );
document.write( "An alternative way to set up the problem is to write an equation which says that, because the distances are the same, the ratio of speeds is equal to the ratio of times.  The initial equation is different; but it leads immediately to the same calculations to solve the problem.<br><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28x%2B144%29%2Fx=9%2F5 ALIGN=MIDDLE  ALT=\"%28x%2B144%29%2Fx=9%2F5\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=9x=5%28x%2B144%29 ALIGN=MIDDLE  ALT=\"9x=5%28x%2B144%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><br><BR>\n" );
document.write( "And from there the solution is the same as above.<br><BR>\n" );
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