SOLUTION: Suppose you have a cookie stand, and when you charge $3 per cookie box you sell 200 boxes. But when you raise your price to $4 you only sell 120 boxes. a. Write an equatio

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Suppose you have a cookie stand, and when you charge $3 per cookie box you sell 200 boxes. But when you raise your price to $4 you only sell 120 boxes. a. Write an equatio      Log On


   

Question 458643: Suppose you have a cookie stand, and when you charge $3 per cookie
box you sell 200 boxes. But when you raise your price to $4 you only
sell 120 boxes.
a. Write an equation for the number of boxes you sell as a function of
the price you charge.
b. Denote "B" for number of boxes, and "P" for the price you charge.
c. Assume the function is linear..
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
Suppose you have a cookie stand, and when you charge $3 per cookie
box you sell 200 boxes. But when you raise your price to $4 you only
sell 120 boxes.
a. Write an equation for the number of boxes you sell as a function of
the price you charge.
b. Denote "B" for number of boxes, and "P" for the price you charge.
c. Assume the function is linear.
..
Since function is linear, we will be using the standard form: y=mx+b, with m=slope, b=y-intercept
For given problem:
B=mP+b
Given are two points on the (P,B) curve,(3,200) and (4,120)
slope, m=∆B/∆P=(200-120)/(3-4)=80/-1=-80
B=-80P+b
plug in B & P from one of given points to solve for b, the y-intercept
200=-80*3+b
b=200+240=440
Equation: B=-80P+440