Expert: Steve Holleran - 9/30/2008

Question
Suppose that a market reseach company finds that at a price of p=$20, they would sell x=$42 tiles each month. If they lower the price to p=$10, they more people would purchase tile, and they can expect to sell x=52 tiles in a month's time. Find the equation of the line for the demand equation. Write your answer in the form of p=mx+b. (Hint: Write an equation using two points in the form (x,p))

Answer
Hi Tino,

From the information you've given, you have two points of information, in the form (x, p):

            (42, 20)    and ( 52, 10)

from these you get the slope of the function m = (20 - 10)/(42 - 52)

                                              = 10 / -10 = -1

then p - 10 = -1(x - 52)

so        p = -1x = 62  would be your function.

Hope this helps
Steve