document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1172512>Question 1172512</A>: <I><SPAN STYLE=\"word-break: break-all;\"> : A bakery discovers that if it decreases the price of its birthday cakes by $1, it sells 12 more<BR>\n" );
document.write( "cakes each month.<BR>\n" );
document.write( "(a) Assuming that monthly sales, M, are related to prices, P, by a linear model, M = aP + b, state<BR>\n" );
document.write( "the value of a.<BR>\n" );
document.write( "(b) If the bakery sells 240 cakes in a month when the price of the cake is $14, work out the value<BR>\n" );
document.write( "of b.<BR>\n" );
document.write( "(c) Use this model to estimate monthly sales when the price is $9.<BR>\n" );
document.write( "(d) If the bakery can make only 168 cakes in a month, work out the price that it needs to charge<BR>\n" );
document.write( "to sell them all </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #797571 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=797571\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The slope is -12, which is a in the equation m=aP+b. Every decrease of cost by $1 is an increase in sales by 12.<BR>\n" );
document.write( "-<BR>\n" );
document.write( "240=-12(14)+b<BR>\n" );
document.write( "$408=b<BR>\n" );
document.write( "------<BR>\n" );
document.write( "price is $9<BR>\n" );
document.write( "M=-12*9+408<BR>\n" );
document.write( "M=$300<BR>\n" );
document.write( "----<BR>\n" );
document.write( "168=-12P+408<BR>\n" );
document.write( "-240=-12P<BR>\n" );
document.write( "P=$20<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=graph%28300%2C300%2C-10%2C25%2C-100%2C500%2C-12x%2B408%2C240%2C168%29 ALIGN=MIDDLE  ALT=\"graph%28300%2C300%2C-10%2C25%2C-100%2C500%2C-12x%2B408%2C240%2C168%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );