document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=521731>Question 521731</A>: <I><SPAN STYLE=\"word-break: break-all;\"> amy drove 200 miles at an average speed 10 miles per hour faster than her usual speed. if she completed the trip in 1 hour less time than usual, what is her usual driving speed in miles per hour? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #346568 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=346568\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> amy drove 200 miles at an average speed 10 miles per hour faster than her usual speed. if she completed the trip in 1 hour less time than usual, what is her usual driving speed in miles per hour?<BR>\n" );
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document.write( "Early trip DATA:<BR>\n" );
document.write( "distance = 200 miles;  rate = r+10 mph ; time = 200/(r+10) hrs<BR>\n" );
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document.write( "Later trip DATA: <BR>\n" );
document.write( "distance = 200 miles : rate = r mph ; time = 200/r hrs<BR>\n" );
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document.write( "Equation:<BR>\n" );
document.write( "early time - later time = 1 hr<BR>\n" );
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document.write( "200/r - 200/(r+10) =  1 hr.<BR>\n" );
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document.write( "200(r+10) - 200r = r(r+10)<BR>\n" );
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document.write( "200*10 = r^2+10r<BR>\n" );
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document.write( "r^2 + 10r - 2000 = 0<BR>\n" );
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document.write( "(r-40)(r+50) = 0<BR>\n" );
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document.write( "Positive Solution:<BR>\n" );
document.write( "rate = 40 mph<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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document.write( "  </SPAN>\n" );
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