document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=186702>Question 186702</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I am confused as to how an quadratic equation can be used in our every day lives? I need an example such as when cooking. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #140039 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=140039\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Here is one involving food that came up some time ago. Perhaps this will help<BR>\n" );
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document.write( "A restaurant sells about 330 sandwiches each day at a price of $6 each.<BR>\n" );
document.write( " For each $.25 decrease in price, 15 more sandwiches are sold per day.<BR>\n" );
document.write( " How much should the restaurant charge to maximize daily revenue?<BR>\n" );
document.write( "What is the maximum daily revenue?<BR>\n" );
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document.write( "Let x = amt ($) decrease in price<BR>\n" );
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document.write( "Since there is an increase of 15 for each $.25 decrease, $1 decrease: 4*15 = 60<BR>\n" );
document.write( "Let 60x = increase in sandwiches sold<BR>\n" );
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document.write( "Price = (6 - x)<BR>\n" );
document.write( "Number sold = (330 + 60x)<BR>\n" );
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document.write( "Revenue = price * number sold: Let y = Revenue:<BR>\n" );
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document.write( "y = (6-x)(330+60x)<BR>\n" );
document.write( "FOIL<BR>\n" );
document.write( "y = 1980 + 360x -330x - 60x^2<BR>\n" );
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document.write( "A quadratic equation:<BR>\n" );
document.write( "y = -60x^2 + 30x + 1980<BR>\n" );
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document.write( "Find the axis of symmetry: x = -b/(2a); a=-60; b=+30<BR>\n" );
document.write( "x = -30/(2*-60)<BR>\n" );
document.write( "x = -30/-120<BR>\n" );
document.write( "x = +.25<BR>\n" );
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document.write( "Max revenue occurs at 6 - .25 = $5.75 for the sandwich<BR>\n" );
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document.write( "Find Max revenue: The problem states that for every $.25, they sell 15 more:<BR>\n" );
document.write( "(330+15) * 5.75 = $1983.75 is the max revenue.<BR>\n" );
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