document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=169766>Question 169766</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Two trains horizontal one eastbound, one westbound, leave a city at the same time. The speed of the westbound train is 20 miles per hour greater than the speed of the eastbound train. After 7 hours, the distance between the westbound train and the eastbound train is 770 miles. Find the speed of the two trains. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #125228 by </B><A HREF=/tutors/aboutme.mpl?userid=solver91311><B>solver91311(24713)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=solver91311><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=solver91311><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=125228\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> If the speed of the faster train is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r ALIGN=MIDDLE  ALT=\"r\"   DISABLED_style= \"max-width:90%; height:auto;\" > then the speed of the slower train must be <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r-20 ALIGN=MIDDLE  ALT=\"r-20\"   DISABLED_style= \"max-width:90%; height:auto;\" >.  Since the trains are going in opposite directions, the speed that they are moving relative to each other is the sum of their speeds, or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r+%2B+r+-20 ALIGN=MIDDLE  ALT=\"r+%2B+r+-20\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "Since distance equals rate times time, or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d=rt ALIGN=MIDDLE  ALT=\"d=rt\"   DISABLED_style= \"max-width:90%; height:auto;\" > and the distance is given as 770 miles and the time as 7 hours, we can say:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=770=%28r%2Br-20%297 ALIGN=MIDDLE  ALT=\"770=%28r%2Br-20%297\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=770=%282r-20%297 ALIGN=MIDDLE  ALT=\"770=%282r-20%297\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=770=14r-140 ALIGN=MIDDLE  ALT=\"770=14r-140\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=14r=910 ALIGN=MIDDLE  ALT=\"14r=910\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r+=+910%2F14+=+65 ALIGN=MIDDLE  ALT=\"r+=+910%2F14+=+65\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "So the westbound (faster) train was going 65 mph, and the eastbound (slower) train was going 20 mph less than that or 45 mph.\r<BR>\n" );
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document.write( "Check:  The sum of the speeds is 65 + 45 = 110.  7 hours at 110 mph is 770 miles.  Answer checks. </SPAN>\n" );
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