document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=311992>Question 311992</A>: <I><SPAN STYLE=\"word-break: break-all;\"> An airplane flying with the wind can cover 600 miles in two hours. The return trip against the wind takes two and one half hours. What is the speed of the plane 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 #223068 by </B><A HREF=/tutors/aboutme.mpl?userid=mananth><B>mananth(16946)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=mananth><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=mananth><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=223068\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> let speed of plane in still air be x<BR>\n" );
document.write( "let speed of wind be y<BR>\n" );
document.write( "..<BR>\n" );
document.write( "speed with wind = x+y<BR>\n" );
document.write( "2(x+y)=600<BR>\n" );
document.write( "..<BR>\n" );
document.write( "speed against wind = x-y<BR>\n" );
document.write( "2.5(x-y)=600<BR>\n" );
document.write( "multiply by 10<BR>\n" );
document.write( "25x-25y= 6000( multiply by 2)<BR>\n" );
document.write( "2x+2y=600 ( multiply by 25)<BR>\n" );
document.write( "ADD<BR>\n" );
document.write( "..<BR>\n" );
document.write( "50x-50y+50x+50y= 12000 +15000<BR>\n" );
document.write( "100x=27000<BR>\n" );
document.write( "x=270 mph speed in still air </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );