The given polynomial is
x^3 - 7x - 6
We would equate eaxh factor to zero, solve for x to get the root. We would substitute the value of x into the polynomial. If the result is zero, then it is a factor. We have
Considering x + 1,
x + 1 = 0
x = - 1
Substituting x = - 1 into the polynomial, it becomes
(- 1)^3 - 7(- 1) - 6
- 1 + 7 - 6
= 6 - 6 = 0
Since the result is zero, x = - 1 is a root. Thus, the correct option is
D. x + 1
