document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1143009>Question 1143009</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A plane can fly 280 miles in the same time as it takes a car to go 100 miles. If the car travels 90 mph slower than the plane, find the speed of the plane. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #763754 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><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=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=763754\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> plane flies 280 miles in the same time as it takes a car to go 100 miles.<BR>\n" );
document.write( "the car travels 90 miles per hour slower than the plane.<BR>\n" );
document.write( "find the speed of the plane.\r<BR>\n" );
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document.write( "r * t = d<BR>\n" );
document.write( "r = rate<BR>\n" );
document.write( "t = time<BR>\n" );
document.write( "d = distance\r<BR>\n" );
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document.write( "for the plane, r * t = d becomes x * t = 280<BR>\n" );
document.write( "for the car, r * t = d becomes (x-90) * t = 100\r<BR>\n" );
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document.write( "x represents the speed of the plane.<BR>\n" );
document.write( "x-90 represents the speed of the car.\r<BR>\n" );
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document.write( "t represents time in both equations because the time in both equations is the same.\r<BR>\n" );
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document.write( "in the first equation, solve for t to get t = 280 / x<BR>\n" );
document.write( "in the second equation replace t with 280 / x to get (x-90) * 280/x = 100<BR>\n" );
document.write( "simplify this equation to get 280 - 90 * 280 / x = 100<BR>\n" );
document.write( "simplify further to get 280 - 25200 / x = 100<BR>\n" );
document.write( "subtract 280 from both sides of the equation to get -25200 / x = -180<BR>\n" );
document.write( "multiply both sides of the equation by x to get -25200 = -180 * x<BR>\n" );
document.write( "divide both sides of the equation by -180 and solve for x to get x = -25200 / -180 = 140\r<BR>\n" );
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document.write( "the plane flies at 140 miles per hour.<BR>\n" );
document.write( "the car drives at 50 miles per hour (140 - 90 = 50).<BR>\n" );
document.write( "for the plane, 140 * t = 280 which gets you t = 280 / 140 = 2.<BR>\n" );
document.write( "for the car, 50 * t = 100 which gets you t = 100 / 50 = 2.\r<BR>\n" );
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document.write( "both the car and the plane take 2 hours to travel their respective distances.<BR>\n" );
document.write( "your solution is the speed of the plane is 140 miles per hour.\r<BR>\n" );
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document.write( " </SPAN>\n" );
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