Question 5887
when P=1 --> C=60
when P=2 --> C=30


imagine a grpah of C against P...just like y-against-x.


We have 2 coordinates (1, 60) and (2, 30). Now, assuming it is linear, we can find the gradient, m from:


m = {{{(y[2] - y[1])/(x[2] - x[1])}}}

m = (60-30)/(1-2)
m = 30/-1
m = -30


so, from the general equation of a straight line, y=mx+c, we now know that y=-30x+c. Now for c. To find this, we need to know both "x" and "y"...which we do: we have 2 sets of points. So pick one of them..i chose (1,60):


60 = -30(1) + c
60 = -30 + c
c = 90


so, equation is now C = -30P + 90


jon.