Ok I got a problem that I am confused with?

Question

a. 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

you need to make the two points like (42,20) and (52,10). then u put in y2-y1/x2-x1 so 10-20/52-42  -10/10=-1 then use point slope which is y-y1=slope(x-x1) so y-10=-1(x-52) y-10=-x+52 Your answer is p=-x+62