[tex]f(x)=\dfrac{x}{2}-3,\ g(x)=3x^2+x-6\\\\(f+g)(x)=f(x)+g(x)=\left(\dfrac{x}{2}-3\right)+(3x^2+x-6)=\dfrac{1}{2}x-3+3x^2+x-6\\\\=3x^2+1\dfrac{1}{2}x-9[/tex]
[tex]Answer:\ \boxed{B.\ 3x^2+\dfrac{3}{2}x-9}}[/tex]
