document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=930282>Question 930282</A>: <I><SPAN STYLE=\"word-break: break-all;\"> an express train takes 1.5 hour less that a passenger train to travel 180 km distance. the speed of the express train is 20 km/hr more than passenger train. find speed of both trains?<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #564944 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=564944\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> x = speed of express train<BR>\n" );
document.write( "y = speed of passenger train<BR>\n" );
document.write( "t = time of passenger train<BR>\n" );
document.write( "---<BR>\n" );
document.write( "s = d/t<BR>\n" );
document.write( "---<BR>\n" );
document.write( "express train:<BR>\n" );
document.write( "x = 180/(t - 1.5)<BR>\n" );
document.write( "---<BR>\n" );
document.write( "passenger train:<BR>\n" );
document.write( "y = 180/t<BR>\n" );
document.write( "---<BR>\n" );
document.write( "x = y + 20<BR>\n" );
document.write( "180/(t - 1.5) = 180/t + 20<BR>\n" );
document.write( "180/(t - 1.5) - 180/t = 20<BR>\n" );
document.write( "180t/t(t - 1.5) - 180(t - 1.5)/t(t - 1.5) = 20<BR>\n" );
document.write( "180t - 180(t - 1.5)= 20t(t - 1.5)<BR>\n" );
document.write( "180t - 180t + 1.5*180 = 20tt - 1.5*20t<BR>\n" );
document.write( "20tt - 1.5*20t - 1.5*180 = 0<BR>\n" );
document.write( "tt - 1.5t - 13.5 = 0<BR>\n" );
document.write( "---<BR>\n" );
document.write( "the above quadratic equation is in standard form, with a=1, b=-1.5 and c=-13.5<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 -1.5 -13.5<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( "t = 4.5<BR>\n" );
document.write( "t = -3<BR>\n" );
document.write( "---<BR>\n" );
document.write( "the negative root doesn't fit the problem statement, so use the positive root:<BR>\n" );
document.write( "---<BR>\n" );
document.write( "t = 4.5<BR>\n" );
document.write( "x = 180/(t - 1.5)<BR>\n" );
document.write( "x = 180/(4.5 - 1.5)<BR>\n" );
document.write( "x = 60<BR>\n" );
document.write( "y = 180/t<BR>\n" );
document.write( "y = 180/4.5<BR>\n" );
document.write( "y = 40<BR>\n" );
document.write( "---<BR>\n" );
document.write( "answer:<BR>\n" );
document.write( "x = speed of express train = 60 kph<BR>\n" );
document.write( "y = speed of passenger train = 40 kph<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, 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 </SPAN>\n" );
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