document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=654747>Question 654747</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Jack drove 600 miles to a convention in Washington D.C. On the return trip he was able to increase his speed by 10mph and saved 3 hours of driving time. Find his rate for each direction. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #408837 by </B><A HREF=/tutors/aboutme.mpl?userid=lwsshak3><B>lwsshak3(11628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lwsshak3><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=408837\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Jack drove 600 miles to a convention in Washington D.C. On the return trip he was able to increase his speed by 10mph and saved 3 hours of driving time. Find his rate for each direction.<BR>\n" );
document.write( "**<BR>\n" );
document.write( "let x=rate of speed to Washington D.C.<BR>\n" );
document.write( "x+10=rate of speed for return trip<BR>\n" );
document.write( "distance/rate of speed=travel time<BR>\n" );
document.write( "600/x-600/(x+10)=3<BR>\n" );
document.write( "LCD:x(x+10)<BR>\n" );
document.write( "600(x+10)-600x=3x^2+30x<BR>\n" );
document.write( "600x+6000-600x=3x^2+30x<BR>\n" );
document.write( "3x^2+30x-6000=0<BR>\n" );
document.write( "x^2+10x-2000=0<BR>\n" );
document.write( "(x+40)(x-50)=0<BR>\n" );
document.write( "x=-40(reject, x>0)<BR>\n" );
document.write( "or<BR>\n" );
document.write( "x=50<BR>\n" );
document.write( "x+10=60<BR>\n" );
document.write( "..<BR>\n" );
document.write( "rate of speed to Washington D.C.=50 mph<BR>\n" );
document.write( "rate of speed for return trip=60 mph </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );