document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=192773>Question 192773</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A plane cruises at 180mph in calm air.  If the plane flies 7 miles with the wind in the same amount of time as it flies 5 miles against the wind, then what is the speed? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #144699 by </B><A HREF=/tutors/aboutme.mpl?userid=RAY100><B>RAY100(1637)</B></A><img src=\"/images/stars/stars-12.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=RAY100><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=144699\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> dist =vel *time<BR>\n" );
document.write( "divide  by  vel<BR>\n" );
document.write( "time=distance/velocity\r<BR>\n" );
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document.write( "Let  x= wind  velocity  <BR>\n" );
document.write( "given  base  velocity  of  180\r<BR>\n" );
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document.write( "1)  7/(180+x)    =time  with  wind\r<BR>\n" );
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document.write( "2)  5/ (180-x) =  time  against  wind\r<BR>\n" );
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document.write( "given  t1=t2\r<BR>\n" );
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document.write( "7/(180+x)  =5/(180-x)\r<BR>\n" );
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document.write( "cross  multiply\r<BR>\n" );
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document.write( "7(180-x)=5(180+x)\r<BR>\n" );
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document.write( "1260-7x=900+5x\r<BR>\n" );
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document.write( "subt  900,  add  7x  to  each  side\r<BR>\n" );
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document.write( "1260-900=5x+7x<BR>\n" );
document.write( "360=12x<BR>\n" );
document.write( "divide  by  12<BR>\n" );
document.write( "30  = x       ANSWER  (MPH)\r<BR>\n" );
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document.write( "check<BR>\n" );
document.write( "7/(180+30)=5/(180-30)\r<BR>\n" );
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document.write( "7/210=5/150<BR>\n" );
document.write( ".0333=.0333   ok </SPAN>\n" );
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