document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=550389>Question 550389</A>: <I><SPAN STYLE=\"word-break: break-all;\"> an express train makes a run of 240 km at acertain speed. Another train whose speed is 12 km/hr less takes an hour longer to cover the same distance. find the speed of the express train in km/hr. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #358704 by </B><A HREF=/tutors/aboutme.mpl?userid=josmiceli><B>josmiceli(19441)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josmiceli><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=josmiceli><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=358704\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=s ALIGN=MIDDLE  ALT=\"s\"   DISABLED_style= \"max-width:90%; height:auto;\" > = speed of express train<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+-+12+ ALIGN=MIDDLE  ALT=\"+s+-+12+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = speed of slower train<BR>\n" );
document.write( "Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+ ALIGN=MIDDLE  ALT=\"+t+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = time for express train to cover <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+240+ ALIGN=MIDDLE  ALT=\"+240+\"   DISABLED_style= \"max-width:90%; height:auto;\" > km<BR>\n" );
document.write( "------------<BR>\n" );
document.write( "Express train:<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+240+=+s%2At+ ALIGN=MIDDLE  ALT=\"+240+=+s%2At+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Slower train:<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+240+=+%28+s+-+12+%29%2A%28+t+%2B+1+%29+ ALIGN=MIDDLE  ALT=\"+240+=+%28+s+-+12+%29%2A%28+t+%2B+1+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "-------------------------<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+240+=+s%2At+-+12t+%2B+s+-+12+ ALIGN=MIDDLE  ALT=\"+240+=+s%2At+-+12t+%2B+s+-+12+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Substitute (1) into (2)<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s%2At+=+s%2At+-+12t+%2B+s+-+12+ ALIGN=MIDDLE  ALT=\"+s%2At+=+s%2At+-+12t+%2B+s+-+12+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+12t+=+s+-+12+ ALIGN=MIDDLE  ALT=\"+12t+=+s+-+12+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+%281%2F12%29%2As+-+1+ ALIGN=MIDDLE  ALT=\"+t+=+%281%2F12%29%2As+-+1+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Substitute this into (1)<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+240+=+s%2A%28+%281%2F12%29%2As+-+1+%29+ ALIGN=MIDDLE  ALT=\"+240+=+s%2A%28+%281%2F12%29%2As+-+1+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+240+=+%281%2F12%29%2As%5E2+-+s+ ALIGN=MIDDLE  ALT=\"+240+=+%281%2F12%29%2As%5E2+-+s+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2880+=+s%5E2+-+12s+ ALIGN=MIDDLE  ALT=\"+2880+=+s%5E2+-+12s+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s%5E2+-+12s+=+2880+ ALIGN=MIDDLE  ALT=\"+s%5E2+-+12s+=+2880+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Complete the square<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s%5E2+-+12s+%2B+%2812%2F2%29%5E2+=+2880+%2B+%2812%2F2%29%5E2+ ALIGN=MIDDLE  ALT=\"+s%5E2+-+12s+%2B+%2812%2F2%29%5E2+=+2880+%2B+%2812%2F2%29%5E2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s%5E2+-+12s+%2B+36+=+2880+%2B+36+ ALIGN=MIDDLE  ALT=\"+s%5E2+-+12s+%2B+36+=+2880+%2B+36+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%28+s+-+6+%29%5E2+=+2916+ ALIGN=MIDDLE  ALT=\"+%28+s+-+6+%29%5E2+=+2916+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%28+s+-+6+%29%5E2+=+54%5E2+ ALIGN=MIDDLE  ALT=\"+%28+s+-+6+%29%5E2+=+54%5E2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+-+6+=+54+ ALIGN=MIDDLE  ALT=\"+s+-+6+=+54+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+=+60+ ALIGN=MIDDLE  ALT=\"+s+=+60+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "The speed of the express train is 60 km/hr<BR>\n" );
document.write( "check answer:<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+240+=+s%2At+ ALIGN=MIDDLE  ALT=\"+240+=+s%2At+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+240+=+60t+ ALIGN=MIDDLE  ALT=\"+240+=+60t+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+4+ ALIGN=MIDDLE  ALT=\"+t+=+4+\"   DISABLED_style= \"max-width:90%; height:auto;\" > hrs<BR>\n" );
document.write( "and<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+240+=+%28+60+-+12+%29%2A%28+t+%2B+1+%29+ ALIGN=MIDDLE  ALT=\"+240+=+%28+60+-+12+%29%2A%28+t+%2B+1+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+240+=+48%2A%28+t+%2B+1+%29+ ALIGN=MIDDLE  ALT=\"+240+=+48%2A%28+t+%2B+1+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+240+=+48t+%2B+48+ ALIGN=MIDDLE  ALT=\"+240+=+48t+%2B+48+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+48t+=+192+ ALIGN=MIDDLE  ALT=\"+48t+=+192+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+4+ ALIGN=MIDDLE  ALT=\"+t+=+4+\"   DISABLED_style= \"max-width:90%; height:auto;\" > hrs<BR>\n" );
document.write( "OK </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );