In this case, we know [tex]g(x) = x + 3[/tex], and we are trying to find [tex]g^{-1}(7)[/tex].
So, we will need to find [tex]g^{-1}(x)[/tex]. Let's do that now:
[tex]y = x + 3[/tex]
[tex]x = y + 3[/tex]
[tex]y = x - 3[/tex]
[tex]g^{-1}(x) = x - 3[/tex]
Now, we are going to solve for when [tex]x = 7[/tex]. To do this, simply "plug in" 7 for [tex]x[/tex] in the inverse function.
[tex]g^{-1}(7) = 7 - 3 = \boxed{4}[/tex]
Our answer is 4.