document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=545499>Question 545499</A>: <I><SPAN STYLE=\"word-break: break-all;\"> MOTION PROBLEMS<BR>\n" );
document.write( "Can you please help me solve this problem:\r<BR>\n" );
document.write( "\n" );
document.write( "An airplane flew for 4 hours with a 20-km/h tail wind. The return flight against the same wind took 5 hours. Find 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 #355603 by </B><A HREF=/tutors/aboutme.mpl?userid=nerdybill><B>nerdybill(7384)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=nerdybill><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=nerdybill><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=355603\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> An airplane flew for 4 hours with a 20-km/h tail wind. The return flight against the same wind took 5 hours. Find the speed of the plane in still air.<BR>\n" );
document.write( ".<BR>\n" );
document.write( "Let x = speed of plane in still air<BR>\n" );
document.write( "then<BR>\n" );
document.write( "from distance formula:<BR>\n" );
document.write( "4(x+20) = 5(x-20)<BR>\n" );
document.write( "4x+80 = 5x-100<BR>\n" );
document.write( "80 = x-100<BR>\n" );
document.write( "180 km/hr = x\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );