document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=734020>Question 734020</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A car traveled 1280 miles at a certain speed. If the speed had been 16 mph faster, the trip could have been made in 4 hours less time. what was the speed? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #448683 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=448683\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A car traveled 1280 miles at a certain speed. If the speed had been 16 mph faster, the trip could have been made in 4 hours less time. what was the speed?<BR>\n" );
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document.write( "Slower trip DATA:<BR>\n" );
document.write( "distance = 1280 miles ; speed = x mph ; time = d/r = 1280/x hrs<BR>\n" );
document.write( "--------------------<BR>\n" );
document.write( "Faster trip DATA:<BR>\n" );
document.write( "distance = 1280 miles ; speed = x+16 mph ; time = d/r = 1280/(x+16) hrs<BR>\n" );
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document.write( "Equation:<BR>\n" );
document.write( "time - time = 4 hrs<BR>\n" );
document.write( "1280/x - 1280/(x+16) = 4 hrs<BR>\n" );
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document.write( "1280*16 = 4x(x+16)<BR>\n" );
document.write( "---<BR>\n" );
document.write( "1280*4 = x^2+16x<BR>\n" );
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document.write( "x^2 + 16x - 5120 = 0<BR>\n" );
document.write( "Factor:<BR>\n" );
document.write( "(x-64)(x+80) = 0<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Positive solution:<BR>\n" );
document.write( "x = 64 mph<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "===================== </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );