document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=920200>Question 920200</A>: <I><SPAN STYLE=\"word-break: break-all;\"> If the average speed of a train was increased 10mph, the 300 mile trip it takes would require 1 hour less time. What is the new speed? \r<BR>\n" );
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document.write( "I tried using the formula for distance: Distance = rate x time <BR>\n" );
document.write( "I used time = distance/ rate and got:<BR>\n" );
document.write( "300/ x+10 = 300/x+10 <BR>\n" );
document.write( "but I don't think that works.<BR>\n" );
document.write( "Thanks for helping.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #558213 by </B><A HREF=/tutors/aboutme.mpl?userid=ewatrrr><B>ewatrrr(24785)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ewatrrr><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=ewatrrr><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=558213\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> t = D/r<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=300%2Fx+-+300%2F%28x%2B10%29+=+1hr ALIGN=MIDDLE  ALT=\"300%2Fx+-+300%2F%28x%2B10%29+=+1hr\"   DISABLED_style= \"max-width:90%; height:auto;\" > |Multiplying thru by x(x+10)so as all denominators = 1<BR>\n" );
document.write( "300(x+10) - 300x = 1x(x+10)<BR>\n" );
document.write( "x^2 + 10x - 3000 = 0 (Tossing out the negative solution for unit measure)<BR>\n" );
document.write( "(x+60)(x-50) = 0<BR>\n" );
document.write( "x = 50mph.  New Speed 60mph  (50+10)<BR>\n" );
document.write( "and...checking<BR>\n" );
document.write( "6hr - 5hr = 1hr </SPAN>\n" );
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