Answer:
A. -4d² + 200d - 100 = 1,500
-4d² + 200d - 1,600 = 0
4d² - 200d + 1,600 = 0
d² - 50d + 400 = 0
(d - 10)(d - 40) = 0
d = $10, $40
B. p'(d) = -8d + 200 = 0
8d - 200 = 0
8d = 200
d = $25
C. p(25) = -4(25²) + 200(25) - 100
= -4(625) + 5,000 - 100
= -2,500 + 5,000 - 100
= $2,400