Respuesta :

Answer:

B

Step-by-step explanation:

We are given the two functions:

[tex]f(x) = 8 - 4x - x^3\text{ and } g(x) = x^2 + 7x - 9[/tex]

And we want to find:

[tex]f(x) + g(x)[/tex]

Substitute:

[tex]= (8 - 4x - x^3) + (x^2 + 7x - 9)[/tex]

Rewrite:

[tex]= (-x^3) + (x^2) + (7x - 4x) + (8 - 9)[/tex]

Combine like terms:

[tex]= -x^3 + x^2 +3x -1[/tex]

In conclusion:

[tex]f(x) + g(x) = -x^3 + x^2 +3x -1[/tex]

Hence, our answer is B.