The point-slope form:

- slope
- point
We have the point
and the slope 
Substitute:

Answer:
The function is negative for all real values of x where -6< x < -2
Step-by-step explanation:
Given f(x) = (x + 2)(x + 6)
The graph of the function is as shown in the attached figure.
As shown, we can deduce the following:
The function is positive for all real values of x where x > -2 and x < -6
The function is zero at x = -2 and x = -6
The function is negative for all real values of x where -6 < x <-2
Compare the observations to the given statements:
So, The true statement is The function is negative for all real values of x where -6 < x <-2
Part A:5=2x^2-x^2+13
5=x^2+13
0=x^2+13-5
0=x^2+8
Part B:5=2x^3-x^3+13
5=x^3+13
0=x^3+13-5
0=x^3+8