document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=492864>Question 492864</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 4. Suppose you have a cookie stand, and when you charge $3 per cookie box you sell 200 boxes. But when you raise your price to $4 you only sell 120 boxes. \r<BR>\n" );
document.write( "\n" );
document.write( "a.   Write an equation for the number of boxes you sell as a function of the price you charge. \r<BR>\n" );
document.write( "\n" );
document.write( "b.   Denote \"B\" for number of boxes, and \"P\" for the price you charge.\r<BR>\n" );
document.write( "\n" );
document.write( "c.   Assume the function is linear..                </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #335200 by </B><A HREF=/tutors/aboutme.mpl?userid=josmiceli><B>josmiceli(19441)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josmiceli><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=josmiceli><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=335200\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> I will plot boxes on the x-axis and cost/box on the y-axis<BR>\n" );
document.write( "Us the point-slope formula, which, in general is:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%28+y+-+y%5B1%5D+%29+%2F+%28+x+-+x%5B1%5D+%29+=+%28+y%5B2%5D+-+y%5B1%5D+%29+%2F+%28+x%5B2%5D+-+x%5B1%5D+%29+ ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "In this case, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x+=+B+ ALIGN=MIDDLE  ALT=\"+x+=+B+\"   DISABLED_style= \"max-width:90%; height:auto;\" > and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+y+=+P+ ALIGN=MIDDLE  ALT=\"+y+=+P+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "The given points are:<BR>\n" );
document.write( "(3,200) and (4,120)<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%28+P+-++120+%29+%2F+%28+B+-+4+%29+=+%28+200+-+120+%29+%2F+%28+3+-+4+%29+ ALIGN=MIDDLE  ALT=\"+%28+P+-++120+%29+%2F+%28+B+-+4+%29+=+%28+200+-+120+%29+%2F+%28+3+-+4+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%28+P+-+120+%29+%2F+%28+B+-+4+%29+=+80+%2F+-1+ ALIGN=MIDDLE  ALT=\"+%28+P+-+120+%29+%2F+%28+B+-+4+%29+=+80+%2F+-1+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Multiply both sides by <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+B+-+4+ ALIGN=MIDDLE  ALT=\"+B+-+4+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+P+-+120+=+-80%2A%28+B+-+4+%29+ ALIGN=MIDDLE  ALT=\"+P+-+120+=+-80%2A%28+B+-+4+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+P+=+-80B+%2B+320+%2B+120+ ALIGN=MIDDLE  ALT=\"+P+=+-80B+%2B+320+%2B+120+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+P+=+-80P+%2B+440+ ALIGN=MIDDLE  ALT=\"+P+=+-80P+%2B+440+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "check:<BR>\n" );
document.write( "Does it include the given points?<BR>\n" );
document.write( "(3,200)<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+P+=+-80P+%2B+440+ ALIGN=MIDDLE  ALT=\"+P+=+-80P+%2B+440+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+200+=+-80%2A3+%2B+440+ ALIGN=MIDDLE  ALT=\"+200+=+-80%2A3+%2B+440+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+200+=+-240+%2B+440+ ALIGN=MIDDLE  ALT=\"+200+=+-240+%2B+440+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+200+=+200+ ALIGN=MIDDLE  ALT=\"+200+=+200+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(4,120)<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+120+=+-80%2A4+%2B+440+ ALIGN=MIDDLE  ALT=\"+120+=+-80%2A4+%2B+440+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+120+=+-320+%2B+440+ ALIGN=MIDDLE  ALT=\"+120+=+-320+%2B+440+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+120+=+120+ ALIGN=MIDDLE  ALT=\"+120+=+120+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "OK </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );