Answer:p = (2100 - x)/25
Step-by-step explanation:
According to the law of demand, when the price,p of the brand of MP3 players is is high, the quantity,x of the brand of MP3 players demanded would be low and when the price,p of the brand of MP3 players is is low, the quantity,x of the brand of MP3 players demanded would be high.
To derive the demand equation, we would apply the slope intercept form of equation which is expressed as
y = mx + c
Where
m = slope
c = intercept
The slope, m would be
(y2 - y1)/(x2 - x1)
Slope = (1100 - 100)/(40 - 80) = 1000/-40
Slope = - 25
To find the y intercept, we would substitute m = - 25, y = 1100 and x = 40 into y = mx + c. It becomes
1100 = - 25 × 40 + c
1100 = - 1000 + c
c = 1100 + 1000 = 2100
y = - 25x + 2100
Therefore, the demand equation is
x = - 25p + 2100
25p = 2100 - x
p = (2100 - x)/25
