<PRE><B>Question 20107</B>
a)add the two expressions{{{0.3x^2+400x+550}}}+{{{0.1x^2+50x+800}}}
 = {{{0.4x^2+450x+1350}}}
b)substitute x=500 into above expression
{{{(0.4(500)^2)+450(500)+1350}}}
=100 000+225 000+1350
=$326350
c)Labour={{{(0.3(500)^2)+400(500)+550}}}
 =$275550
  Materials={{{(0.1(500)^2)+50(500)+800}}}
 =$50800.
Or simply Total cost-Labour=Materials
Pete</PRE>