How do I do this first step?
You need a value for x and F(x) before you can find a value for a.
For example, if F(x) = 0 then
x^3 - 2x^2 + x - a = 0
This can be written as
(x - 2)(x^2 + a/2) = 0
In order for this to match the first equation the coefficient of the x term must be 1. That is, a/2 = 1.
i.e. a = 2
