Respuesta :

Answer:

-x^3+x^2+3x-1

Step-by-step explanation:

f(x)=8−4x−x³

g(x)=x²+7x−9

f(x)+g(x) = 8−4x−x³ +x²+7x−9

Combine like terms

             =-x^3+x^2+3x-1

Answer:

See below

Step-by-step explanation:

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

Once

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

[tex](f+g)(x)=(8-4x-x^3)+(x^2+7x-9)=-x^3+x^2+3x-1[/tex]

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