Question

I am so lost, can anyone help me? I don't even understand what the teacher wants out of me with this problem.

Suppose that a market research 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, then more people would purchase the 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 p = mx + b. (Hint: Write an equation using two points in the form (x,p)).

Answer 1

There are to points : (42,20) , (52,10)

m=(20-10)/(42-52)= -1 => m=-1

choose any point from the two points .
(42,20)=(x1,p1)

p-p1=m(x-x1) => p-20=-1(x-42)

p=-x+42+20 => p=-x+62