document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=112878>Question 112878</A>: <I><SPAN STYLE=\"word-break: break-all;\"> This was originally a test question that I tried to figure out. The answer is 160 miles per hour. I just need to know how they got it because I can't. Thank you.\r<BR>\n" );
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document.write( "A plane flew 480 miles at a certain speed; and then increased its speed by 20 miles per hour, and continued on the same course. After having flown a total distance of 840 miles in a total of 5 hours, it landed. What was the original speed of the plain?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #82235 by </B><A HREF=/tutors/aboutme.mpl?userid=scott8148><B>scott8148(6628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=scott8148><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=scott8148><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=82235\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> let x=\"original speed\", so x+20=\"increased speed\" ___ time=distance/rate\r<BR>\n" );
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document.write( "the plane flies 480 mi @ x; and (840-480) mi @ x+20\r<BR>\n" );
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document.write( "(480/x)+(360/(x+20))=5 ___ 480(x+20)+360(x)=5(x)(x+20) ___ 96(x+20)+72(x)=x(x+20)\r<BR>\n" );
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document.write( "0=x^2-148x-1920 ___ 0=(x+12)(x-160) </SPAN>\n" );
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