document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=213913>Question 213913</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Two planes leave simultaneously from the same airport, one flying due east and the other due south. The eastbound plane is flying 100 miles per hour faster than the southbound plane. After 4 hours the planes are 3080 miles apart. Find the speed of each plane. (Use 1 decimal place.) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #161656 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=161656\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Two planes leave simultaneously from the same airport, one flying due east and the other due south. <BR>\n" );
document.write( "The eastbound plane is flying 100 miles per hour faster than the southbound plane. <BR>\n" );
document.write( "After 4 hours the planes are 3080 miles apart.<BR>\n" );
document.write( " Find the speed of each plane. (Use 1 decimal place.)<BR>\n" );
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document.write( "The distance between the planes is the hypotenuse of a right triangle<BR>\n" );
document.write( "a^2 + b^2 = c^2<BR>\n" );
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document.write( "Let s = speed of the southbound plane<BR>\n" );
document.write( "then<BR>\n" );
document.write( "(s+100) = speed of the eastbound<BR>\n" );
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document.write( "Dist = speed * time<BR>\n" );
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document.write( "a = 4s; south distance<BR>\n" );
document.write( "b = 4(s+100); east distance<BR>\n" );
document.write( "c = 3080; distance between the planes after 4 hrs<BR>\n" );
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document.write( "(4s)^2 + (4(s+100))^2 = 3080^2<BR>\n" );
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document.write( "16s^2 + (4s+400)^2 = 9486400<BR>\n" );
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document.write( "16s^2 + (4s+400)^2 = 9486400<BR>\n" );
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document.write( "16s^2 + 16s^2 + 3200s + 160000 = 948640<BR>\n" );
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document.write( "16s^2 + 16s^2 + 3200s + 160000 - 9486400 = 0<BR>\n" );
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document.write( "32s^2 + 3200s - 9326400 = 0<BR>\n" );
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document.write( "Simplify divide by 32:<BR>\n" );
document.write( "s^2 + 100s - 291450 = 0<BR>\n" );
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document.write( "Using the quadratic formula; a=1; b=100; c=291450<BR>\n" );
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document.write( "I got a positive solution of 492.2 mph the south bound plane<BR>\n" );
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document.write( "then 592.2 mph the east bound plane <BR>\n" );
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document.write( "Check solution on a calc; enter <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sqrt%28%284%2A492.2%29%5E2+%2B+%284%2A592.2%29%5E2%29 ALIGN=MIDDLE  ALT=\"sqrt%28%284%2A492.2%29%5E2+%2B+%284%2A592.2%29%5E2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 3080 </SPAN>\n" );
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