document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=254415>Question 254415</A>: <I><SPAN STYLE=\"word-break: break-all;\">  a charter company will provide a plane for a fare of $200 each for 80 or fewer passengers. For each passenger in excess of 80, the fare decreases $2 per person for everyone. What number of passengers would produce for the greatest revenue for the company?\r<BR>\n" );
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document.write( "That is question I need to solve, but what I really need is an equation to use to solve this.<BR>\n" );
document.write( "If so, can you show me how to do step by step? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #186787 by </B><A HREF=/tutors/aboutme.mpl?userid=drk><B>drk(1908)</B></A><img src=\"/images/stars/stars-12.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=drk><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=186787\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> P = (80+x)(200-2x)<BR>\n" );
document.write( "P = is a parabola that opens down. This means there is a maximum profit somewhere.<BR>\n" );
document.write( "P = -2x^2 + 40x + 16000<BR>\n" );
document.write( "We can find the vertex using -b/2a as<BR>\n" );
document.write( "-b/2a = (-40/-4) = 10<BR>\n" );
document.write( "Put in x = 10 and we get<BR>\n" );
document.write( "P = 90*180 = 16200<BR>\n" );
document.write( "Since the number of passengers increases, we get 80+10 = 90.\r<BR>\n" );
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document.write( "90 passengers gives us a profit of $16,200 </SPAN>\n" );
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