document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=966100>Question 966100</A>: <I><SPAN STYLE=\"word-break: break-all;\">  A plane can fly at a rate of 215 mph in calm air. Traveling with the wind the plane flew 750 miles in the same amount of time that it flew 540 miles againstthe wind. Find the rate 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 #590492 by </B><A HREF=/tutors/aboutme.mpl?userid=ikleyn><B>ikleyn(52781)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ikleyn><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=ikleyn><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=590492\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> \r<BR>\n" );
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document.write( "Let &nbsp;x&nbsp; be the wind speed (=rate), &nbsp;in <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=miles%2Fhour ALIGN=MIDDLE  ALT=\"miles%2Fhour\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "Then the speed of the plane when flying with the wind is &nbsp;215 + x&nbsp; <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=miles%2Fhour ALIGN=MIDDLE  ALT=\"miles%2Fhour\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "The speed of the plane when flying against the wind is &nbsp;215 - x&nbsp; <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=miles%2Fhour ALIGN=MIDDLE  ALT=\"miles%2Fhour\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "The plane covers the distance of &nbsp;750&nbsp; miles in &nbsp;<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=750%2F%28215+%2B+x%29 ALIGN=MIDDLE  ALT=\"750%2F%28215+%2B+x%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >&nbsp; flying with the wind.\r<BR>\n" );
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document.write( "The plane covers the distance of &nbsp;540&nbsp; miles in &nbsp;<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=540%2F%28215+-+x%29 ALIGN=MIDDLE  ALT=\"540%2F%28215+-+x%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >&nbsp; flying against the wind.\r<BR>\n" );
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document.write( "So, &nbsp;you have an equation &nbsp;<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=750%2F%28215+%2B+x%29 ALIGN=MIDDLE  ALT=\"750%2F%28215+%2B+x%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=540%2F%28215+-+x%29 ALIGN=MIDDLE  ALT=\"540%2F%28215+-+x%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > to find &nbsp;<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x ALIGN=MIDDLE  ALT=\"x\"   DISABLED_style= \"max-width:90%; height:auto;\" >. \r<BR>\n" );
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document.write( "Multiply both sides by &nbsp;<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28215+%2B+x%29%2A%28215+-+x%29 ALIGN=MIDDLE  ALT=\"%28215+%2B+x%29%2A%28215+-+x%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >. &nbsp;You will get \r<BR>\n" );
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document.write( "750*(215-x) = 540*(215+x). \r<BR>\n" );
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document.write( "Divide both sides by &nbsp;30. &nbsp;You will get \r<BR>\n" );
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document.write( "25*(215-x) = 18*(215+x).\r<BR>\n" );
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document.write( "Open parentheses; &nbsp;collect the &nbsp;x-terms in the right side; &nbsp;collect the constant terms in the left side:\r<BR>\n" );
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document.write( "25*215 - 18*215 = 18*x + 25*x, &nbsp;or\r<BR>\n" );
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document.write( "7*215 = 43x.\r<BR>\n" );
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document.write( "Divide both sides by 43. &nbsp;You will get \r<BR>\n" );
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document.write( "x = 7*5 = 35.\r<BR>\n" );
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document.write( "<B>Answer</B>. The rate of wind is &nbsp;35 <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=miles%2Fhour ALIGN=MIDDLE  ALT=\"miles%2Fhour\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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