document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=582187>Question 582187</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The profit P, in dollars, gained by selling x computers is modeled by the equation P= -5x^2 + 1000x + 5000. Find the number of computers that must be sold to obtain a profit of $55,000.00? <BR>\n" );
document.write( "Using the quadratic equation, I came up with the computer cost being $41.42 then divided $55,000 by that and came out with 1327.86 computers needed to be sold to obtain that profit of $55,000. <BR>\n" );
document.write( "Please help. <BR>\n" );
document.write( "Diana </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #371985 by </B><A HREF=/tutors/aboutme.mpl?userid=dfrazzetto><B>dfrazzetto(283)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=dfrazzetto><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=dfrazzetto><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=371985\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> P= -5x^2 + 1000x + 5000\r<BR>\n" );
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document.write( "55000 = -5x^2 + 1000x + 5000\r<BR>\n" );
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document.write( "To use quadratic, we need the left side to be zero:\r<BR>\n" );
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document.write( "0 = -5x^2 + 1000x + 5000 - 55000\r<BR>\n" );
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document.write( "0 = -5x^2 + 1000x - 50000\r<BR>\n" );
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document.write( "Divide by -5:\r<BR>\n" );
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document.write( "0 = x^2 - 200x + 10000\r<BR>\n" );
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document.write( "factors into 0= (x-100)^2\r<BR>\n" );
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document.write( "x=100 computers\r<BR>\n" );
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document.write( "CHECK:\r<BR>\n" );
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document.write( " P= -5x^2 + 1000x + 5000.\r<BR>\n" );
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document.write( " P= -5(100)^2 + 1000(100) + 5000.\r<BR>\n" );
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document.write( "P = -50,000 + 100,000 + 50000\r<BR>\n" );
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document.write( "P = 55,000&#8730; </SPAN>\n" );
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