Question 492864
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.
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You have two points: (3,200) and (4,120)
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a. Write an equation for the number of boxes you sell as a function of the price you charge.
slope = (200-120)/(3-4) = -80
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Form: # of boxes = mp + b
Solve for 200 = -80*3 + b
b = 440
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Equation:
# of boxes = -80(charge) + 440

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b. Denote "B" for number of boxes, and "P" for the price you charge.
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c. Assume the function is linear..
B = -80*P + 440
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Cheers,
Stan H.
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