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 #567647 by </B><A HREF=/tutors/aboutme.mpl?userid=TimothyLamb><B>TimothyLamb(4379)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=TimothyLamb><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=TimothyLamb><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=567647\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> x = speed on first part<BR>\n" );
document.write( "y = speed on second part<BR>\n" );
document.write( "x = y + 20<BR>\n" );
document.write( "y = x - 20<BR>\n" );
document.write( "---<BR>\n" );
document.write( "s = d/t<BR>\n" );
document.write( "t = d/s<BR>\n" );
document.write( "---<BR>\n" );
document.write( "time on first part:<BR>\n" );
document.write( "t = time on first part<BR>\n" );
document.write( "t = 160/x<BR>\n" );
document.write( "---<BR>\n" );
document.write( "time on second part:<BR>\n" );
document.write( "4 - t = 80/y<BR>\n" );
document.write( "4 - t = 80/(x - 20)<BR>\n" );
document.write( "t = 4 - 80/(x - 20)<BR>\n" );
document.write( "---<BR>\n" );
document.write( "equate times:<BR>\n" );
document.write( "160/x = 4 - 80/(x - 20)<BR>\n" );
document.write( "160/x + 80/(x - 20) = 4<BR>\n" );
document.write( "160(x - 20)/x(x - 20) + 80x/x(x - 20) = 4<BR>\n" );
document.write( "160(x - 20) + 80x = 4x(x - 20)<BR>\n" );
document.write( "160x - 3200 + 80x = 4xx - 80x<BR>\n" );
document.write( "4xx - 80x - 80x - 160x + 3200 = 0<BR>\n" );
document.write( "4xx - 320x + 3200 = 0<BR>\n" );
document.write( "xx - 80x + 800 = 0<BR>\n" );
document.write( "---<BR>\n" );
document.write( "the above quadratic equation is in standard form, with a=1, b=-80 and c=800<BR>\n" );
document.write( "---<BR>\n" );
document.write( "to solve the quadratic equation, by using the quadratic formula, copy and paste this:<BR>\n" );
document.write( "1 -80 800<BR>\n" );
document.write( "into this solver: https://sooeet.com/math/quadratic-equation-solver.php<BR>\n" );
document.write( "---<BR>\n" );
document.write( "the quadratic has two real roots at:<BR>\n" );
document.write( "---<BR>\n" );
document.write( "x = 68.2842712<BR>\n" );
document.write( "x = 11.7157288<BR>\n" );
document.write( "---<BR>\n" );
document.write( "the root x=11.7 would make y negative, which doesn't fit the problem statement, so use the first root:<BR>\n" );
document.write( "---<BR>\n" );
document.write( "answer:<BR>\n" );
document.write( "x = speed on first part = 68.2842712 mph<BR>\n" );
document.write( "y = speed on second part = 48.2842712 mph<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Free algebra tutoring live chat:<BR>\n" );
document.write( "https://sooeet.com/chat.php?gn=algebra<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Solve and graph linear equations:<BR>\n" );
document.write( "https://sooeet.com/math/linear-equation-solver.php<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Solve quadratic equations with quadratic formula:<BR>\n" );
document.write( "https://sooeet.com/math/quadratic-formula-solver.php<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Solve systems of linear equations up to 6-equations 6-variables:<BR>\n" );
document.write( "https://sooeet.com/math/system-of-linear-equations-solver.php<BR>\n" );
document.write( "--- </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );