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.