Given
[tex]\begin{gathered} f(x)=\frac{x}{3}-2 \\ g(x)=3x^2+2x-6 \end{gathered}[/tex]We want to find (f + g)(x). This is basically the sum function of f and g.
We add the two functions and simplify. The steps are shown below:
[tex]\begin{gathered} (f+g)(x)=f(x)+g(x) \\ =(\frac{x}{3}-2)+(3x^2+2x-6) \\ =\frac{x}{3}-2+3x^2+2x-6 \\ =3x^2+2x+\frac{x}{3}-2-6 \\ =3x^2+\frac{7}{3}x-8 \end{gathered}[/tex]The correct answer is:
[tex](f+g)(x)=3x^2+\frac{7}{3}x-8[/tex]