document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=29963>Question 29963</A>: <I><SPAN STYLE=\"word-break: break-all;\"> when ace airlines changed to planes that flew 100 km/h faster than its old ones, the time of its 2800 km Dallas-Seattle flight was reduced by 30 min. Find the speed of the new planes. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #16735 by </B><A HREF=/tutors/aboutme.mpl?userid=Paul><B>Paul(988)</B></A><img src=\"/images/stars/stars-11.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Paul><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=16735\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> let the speed be x (orignal)<BR>\n" );
document.write( "increased speed = x+100<BR>\n" );
document.write( "30 minutes =0.5hours<BR>\n" );
document.write( "Equation:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2800%2F%28x%2B100%29-2800%2Fx=0.5 ALIGN=MIDDLE  ALT=\"2800%2F%28x%2B100%29-2800%2Fx=0.5\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2800%28%28x%2B100%29-%28x%29%29=0.5%28%28x%29%28x%2B100%29%29 ALIGN=MIDDLE  ALT=\"2800%28%28x%2B100%29-%28x%29%29=0.5%28%28x%29%28x%2B100%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2800%28100%29=0.5%28x%5E2%2B100x%29 ALIGN=MIDDLE  ALT=\"2800%28100%29=0.5%28x%5E2%2B100x%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=280000=0.5x%5E2%2B50x ALIGN=MIDDLE  ALT=\"280000=0.5x%5E2%2B50x\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0.5x%5E2%2B50x-280000=0 ALIGN=MIDDLE  ALT=\"0.5x%5E2%2B50x-280000=0\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=%28-b%2B-sqrt%28b%5E2-4%2Aa%2Ac%29%29%2F%282%2Aa%29 ALIGN=MIDDLE  ALT=\"x=%28-b%2B-sqrt%28b%5E2-4%2Aa%2Ac%29%29%2F%282%2Aa%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "a=0.5, b=50, c=-280000<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=%28-50%2B-sqrt%2850%5E2-4%2A0.5%2A-280000%29%29%2F%282%2A0.5%29 ALIGN=MIDDLE  ALT=\"x=%28-50%2B-sqrt%2850%5E2-4%2A0.5%2A-280000%29%29%2F%282%2A0.5%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Simplfy and you get two solutions:<BR>\n" );
document.write( "x=-800 and x=700<BR>\n" );
document.write( "Remove the negavtive<BR>\n" );
document.write( "x=700<BR>\n" );
document.write( "700+100=800\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "<font color = orange>Hence, the speed of the new planes is 800km/h</font><BR>\n" );
document.write( "Paul.\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );