document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=332174>Question 332174</A>: <I><SPAN STYLE=\"word-break: break-all;\"> a plane travels 2520km in 6 hours with a tailwind, but only 1620 km with a headwind in the same time. Find the speed of the plane and the speed of the wind.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #238079 by </B><A HREF=/tutors/aboutme.mpl?userid=mananth><B>mananth(16949)</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=238079\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 2520km in 6 hours with a tailwind, but only 1620 km with a headwind in the same time.<BR>\n" );
document.write( "let speed of plane be x<BR>\n" );
document.write( "speed of wind be y<BR>\n" );
document.write( "..<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=distance+%2F+speed+=+time ALIGN=MIDDLE  ALT=\"distance+%2F+speed+=+time\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "with tailwind speed = x+y<BR>\n" );
document.write( "with headwind speed = x-y<BR>\n" );
document.write( "..<BR>\n" );
document.write( "Tailwind<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2520%2F%28x%2By%29=6 ALIGN=MIDDLE  ALT=\"2520%2F%28x%2By%29=6\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "2520=6x+6y<BR>\n" );
document.write( "divide by 6<BR>\n" );
document.write( "420= x+y..................1<BR>\n" );
document.write( "Headwind<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2520km+in+6+hours+with+a+tailwind%2C+but+only+1620+km+with+a+headwind+in+the+same+time.%0D%0Alet+speed+of+plane+be+x%0D%0Aspeed+of+wind+be+y%0D%0A..%0D%0A%3CIMG+SRC=%2Fcgi-bin%2Fplot-formula.mpl%3Fexpression=distance%2B%252F%2Bspeed%2B=%2Btime+ALIGN=MIDDLE++ALT=%22distance%2B%252F%2Bspeed%2B=%2Btime%22++ DISABLED_style= %22max-width%3A90%25%3B+height%3Aauto%3B%22+%3E%0D%0Awith+tailwind+speed+=+x%2By%0D%0Awith+headwind+speed+=+x-y%0D%0A..%0D%0ATailwind%0D%0A%3CIMG+SRC=%2Fcgi-bin%2Fplot-formula.mpl%3Fexpression=2520%252F%2528x%252By%2529=6+ALIGN=MIDDLE++ALT=%222520%252F%2528x%252By%2529=6%22++ DISABLED_style= %22max-width%3A90%25%3B+height%3Aauto%3B%22+%3E%0D%0A2520=6x%2B6y%0D%0Adivide+by+6%0D%0A420=+x%2By..................1%0D%0AHeadwind%0D%0A ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" >1620/(x-y)=6<BR>\n" );
document.write( "6x-6y=1620<BR>\n" );
document.write( "divide by 6<BR>\n" );
document.write( "x-y=270..................2<BR>\n" );
document.write( "add equation1 & 2 to eliminate y<BR>\n" );
document.write( "x+y+x-y=420+270<BR>\n" );
document.write( "2x=690<BR>\n" );
document.write( "x=395 mph speed of plane<BR>\n" );
document.write( "..<BR>\n" );
document.write( "x+y=420<BR>\n" );
document.write( "395+y=420<BR>\n" );
document.write( "y=420-395<BR>\n" );
document.write( "y=25 mph speed of wind<BR>\n" );
document.write( "..<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );