document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=762807>Question 762807</A>: <I><SPAN STYLE=\"word-break: break-all;\"> with a wind velocity of 40 kph, it takes an airplane as long to travel 1200 km with the wind as 900 km against it. how fast can the plane travel in still air? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #464217 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=464217\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> with a wind velocity of 40 kph, it takes an airplane as long to travel 1200 km with the wind as 900 km against it. how fast can the plane travel in still air?<BR>\n" );
document.write( "***<BR>\n" );
document.write( "let x=speed of plane in still air<BR>\n" );
document.write( "x+40=speed of plane with the wind<BR>\n" );
document.write( "x-40=speed of plane against the wind<BR>\n" );
document.write( "travel time=distance/speed<BR>\n" );
document.write( "..<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1200%2F%28x%2B40%29=900%2F%28x-40%29 ALIGN=MIDDLE  ALT=\"1200%2F%28x%2B40%29=900%2F%28x-40%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "1200(x-40)=900(x+40)<BR>\n" );
document.write( "1200x-48000=900x+36000<BR>\n" );
document.write( "300x=84000<BR>\n" );
document.write( "x=280<BR>\n" );
document.write( "speed of plane in still air=280 kph </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );