document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=788157>Question 788157</A>: <I><SPAN STYLE=\"word-break: break-all;\"> John drove his moped from Lansing to Detroit, <BR>\n" );
document.write( "a distance of 120 km. He drove 10 km per hour faster on the <BR>\n" );
document.write( "return trip, cutting one hour off of his time. How fast did he <BR>\n" );
document.write( "drive each way?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #478419 by </B><A HREF=/tutors/aboutme.mpl?userid=mananth><B>mananth(16946)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=mananth><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=mananth><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=478419\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> speed there =x<BR>\n" );
document.write( "speed return =y\r<BR>\n" );
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document.write( "Time going - time return = 1 hour\r<BR>\n" );
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document.write( "t=d/r\r<BR>\n" );
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document.write( "120/x - 120/(x+10)=1\r<BR>\n" );
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document.write( "multiply by x(x+10)\r<BR>\n" );
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document.write( "120(x+10)-120x=x^2+10x\r<BR>\n" );
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document.write( "120x+1200-120x=x^2+10x\r<BR>\n" );
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document.write( "x^2+10x-1200=0\r<BR>\n" );
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document.write( "x^2+40x-30x-1200=0\r<BR>\n" );
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document.write( "x(x+40)-30(x+40)=0\r<BR>\n" );
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document.write( "(x+40)(x-30)=0\r<BR>\n" );
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document.write( "x=-40 OR x=30\r<BR>\n" );
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document.write( "ignore negative\r<BR>\n" );
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document.write( "speed there = 30 km/h<BR>\n" );
document.write( "speed return = 40 km/h\r<BR>\n" );
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document.write( " </SPAN>\n" );
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