document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=231976>Question 231976</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Bob drives 200 miles to attend a football game.  His speed on the return trip was an average of 10mph less than his speed to the game.  If the return trip took 1 hour longer, how fast did he drive in both directions?\r<BR>\n" );
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document.write( "I come up with 200/(x-10) - 200/x = 1...  I don't even know if this is right with the D=RT formula ??? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #171563 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=171563\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Bob drives 200 miles to attend a football game.<BR>\n" );
document.write( " His speed on the return trip was an average of 10mph less than his speed to the game. <BR>\n" );
document.write( "If the return trip took 1 hour longer, how fast did he drive in both directions? <BR>\n" );
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document.write( "But that is right! Just continue: Time = dist/speed:<BR>\n" );
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document.write( "slow time - fast time = 1 hr<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=200%2F%28x-10%29 ALIGN=MIDDLE  ALT=\"200%2F%28x-10%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > - <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=200%2Fx ALIGN=MIDDLE  ALT=\"200%2Fx\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 1.<BR>\n" );
document.write( "Multiply by x{x-10)and you have<BR>\n" );
document.write( "200x - 200(x-10) = x(x-10)<BR>\n" );
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document.write( "I made a big mistake here, (-200 * -10 = +2000)<BR>\n" );
document.write( "200x - 200x + 2000 = x^2 - 10x<BR>\n" );
document.write( "Then <BR>\n" );
document.write( "A quadratic equation<BR>\n" );
document.write( "x^2 - 10x - 2000 = 0<BR>\n" );
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document.write( "Factors to:<BR>\n" );
document.write( "(x-50)(x+40) = 0<BR>\n" );
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document.write( "Positive solution<BR>\n" );
document.write( "x = 50 mph is the fast car speed<BR>\n" );
document.write( "and obviously<BR>\n" );
document.write( "40 mph is the slow car speed<BR>\n" );
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document.write( "Check this by finding the times<BR>\n" );
document.write( "200/40 = 5 hr<BR>\n" );
document.write( "200/50 = 4 hr<BR>\n" );
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document.write( "I did this on paper then typed it out wrong, forgive me, I hope I didn't mess you up too much. Carl<BR>\n" );
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