Answer:
a. x = 1 b. 36 c. 36
Step-by-step explanation:
a. At the equilibrium point, D(x) = S(x)
(x - 7)² = x² + 4x + 31
Expanding, we ave
x² - 14x + 49 = x² + 4x + 31
collecting like terms
14x + 4x = 49 - 31
18x = 18
x = 18/18 = 1
b. Substituting x = 1 into D(x), we have
D(1) = (1 - 7)² = (-6)² = 36
c. Substituting x = 1 into S(x), we have
S(1) = 1² + 4(1) + 31 = 1 + 4 + 31 = 36