Answer:
b = 2, c = - 8
Step-by-step explanation:
Given x = a is a root then (x - a) is a factor
Here the roots are x = - 4 and x = 2 , then the corresponding factors are
(x + 4) and (x - 2)
The equation is then the product of the factors , that is
(x + 4)(x - 2) = 0 ← expand factors using FOIL
x² + 2x - 8 = 0
with b = 2 and c = - 8