document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=155941>Question 155941</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A plane flies 300 miles with a tail wind in 1 hour. It takes the same plane 2 hours to fly the 300 miles when flying against the wind. What is the plane's speed 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 #114870 by </B><A HREF=/tutors/aboutme.mpl?userid=ptaylor><B>ptaylor(2198)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ptaylor><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=ptaylor><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=114870\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <BR>\n" );
document.write( "Distance(d) equals Rate(r) times Time(t) or d=rt;  r=d/t and t=d/r\r<BR>\n" );
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document.write( "Let r=rate(speed) of plane in still air<BR>\n" );
document.write( "Let r1=rate (speed) of tailwind\r<BR>\n" );
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document.write( "With tailwind:  300=(r+r1)*1\r<BR>\n" );
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document.write( "300=r+r1-------------------------------eq1\r<BR>\n" );
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document.write( "Against tailwind: 300=(r-r1)*2\r<BR>\n" );
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document.write( "300=2r-2r1------------------------------eq2<BR>\n" );
document.write( "multiply eq1 by 2 and then add it to eq2:\r<BR>\n" );
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document.write( "600=2r+2r1----------eq1a<BR>\n" );
document.write( "300=2r-2r1-------------eq2\r<BR>\n" );
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document.write( "900=4r  divide each side by 4<BR>\n" );
document.write( "r=225 mph---------------------------speed of plane in still air\r<BR>\n" );
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document.write( "substitute r=225 mph into eq1<BR>\n" );
document.write( "300=225+r1  subtract 225 from each side \r<BR>\n" );
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document.write( "300-225=225-225+r1 collect like terms\r<BR>\n" );
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document.write( "75=r1 or<BR>\n" );
document.write( "r1=75 mph----------------------speed of wind\r<BR>\n" );
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document.write( "CK<BR>\n" );
document.write( "300=(225+75)*1<BR>\n" );
document.write( "300=300<BR>\n" );
document.write( "and<BR>\n" );
document.write( "300=(225-75)*2<BR>\n" );
document.write( "300=150*2<BR>\n" );
document.write( "300=300\r<BR>\n" );
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document.write( "Hope this helps--ptaylor<BR>\n" );
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