document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=934632>Question 934632</A>: <I><SPAN STYLE=\"word-break: break-all;\"> On a recent trip, Sarah's car traveled 20 mph faster on the first 160 miles than it did on the remaining 80 miles. The total time for the trip was 4 hr. Find the speed of Sarah's car on the<BR>\n" );
document.write( "first part of the trip </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #567663 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=567663\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> On a recent trip, Sarah's car traveled 20 mph faster on the first 160 miles than it did on the remaining 80 miles. The total time for the trip was 4 hr. Find the speed of Sarah's car on the first part of the trip<BR>\n" );
document.write( "***<BR>\n" );
document.write( "let x=speed of sarah's car for first 160 miles<BR>\n" );
document.write( "(x-20)=speed of sarah's car for remaining 80 miles<BR>\n" );
document.write( "travel time=distance/speed<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=160%2Fx%2B80%2F%28x-20%29=4 ALIGN=MIDDLE  ALT=\"160%2Fx%2B80%2F%28x-20%29=4\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "lcd:x(x-20)<BR>\n" );
document.write( "160x-3200+80x=4x(x-20)<BR>\n" );
document.write( "160x-3200+80x=4x^2-80x<BR>\n" );
document.write( "4x^2-320x+3200=0<BR>\n" );
document.write( "x^2-80x+800=0<BR>\n" );
document.write( "solve for x by quadratic formula:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+ ALIGN=MIDDLE  ALT=\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "a=1, b=-80, c=800<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%2880+%2B-+sqrt%28+6400-4%2A1%2A800+%29%29%2F%282%29+ ALIGN=MIDDLE  ALT=\"x+=+%2880+%2B-+sqrt%28+6400-4%2A1%2A800+%29%29%2F%282%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%2880+%2B-+sqrt%28+6400-3200+%29%29%2F%282%29+ ALIGN=MIDDLE  ALT=\"x+=+%2880+%2B-+sqrt%28+6400-3200+%29%29%2F%282%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%2880+%2B-+sqrt%28+3200+%29%29%2F%282%29+ ALIGN=MIDDLE  ALT=\"x+=+%2880+%2B-+sqrt%28+3200+%29%29%2F%282%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "x=11.72 (reject)<BR>\n" );
document.write( "or<BR>\n" );
document.write( "x=68.28<BR>\n" );
document.write( "speed of sarah's car for first 160 miles=68.28 mph </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );