Answer:
See below.
Step-by-step explanation:
So we know that:
[tex]f(x)=4x+8\text{ and } g(x)=2x-12[/tex]
First, know that:
[tex](f-g)(x)[/tex]
Is the same as:
[tex]=f(x)-g(x)[/tex]
Substitute:
[tex]=(4x+8)-(2x-12)[/tex]
Distribute:
[tex]=4x+8-2x+12[/tex]
Combine like terms;
[tex]=2x+20[/tex]
Thus:
[tex]f(g(x))=2x+20[/tex]
This is simply a linear equation.
Thus, the domain is all real numbers.
In interval notation, this is:
[tex](-\infty, \infty)[/tex]