If f(x)=3xf(x) = 3xf(x)=3x and g(x)=x+2g(x) = x + 2g(x)=x+2, what is (f+g)(x)(f+g)(x)(f+g)(x)?
3x2+6x3x^2 + 6x3x2+6x
4x+24x + 24x+2
3x+23x + 23x+2
6x6x6x