Answer: -2
Step-by-step explanation:
The given functions : [tex]f(x) = x^2-2x\text{ and }g(x) = 6x + 4[/tex]
Then the combine function of the above function is given by :-
[tex](f + g)(x)=\f(x)+g(x)=x^2-2x+6x+4=x^2+4x+4[/tex]
Factorize [tex](f + g)(x)=x^2+4x+4[/tex] by splitting middle term.
[tex]=x^2+2x+2x+4\\\\=x(x+2)+2(x+2)\\\\=(x+2)(x+2)[/tex]
Substitute [tex](f + g)(x) = 0[/tex]
[tex](x+2)(x+2)=0\\\\\Rightarrow\ x=-2[/tex]
Hence, at x=-2 [tex](f + g)(x) = 0[/tex]
