We are given the following functions:
[tex]\begin{gathered} f(x)=-3x+5 \\ g(x)=\frac{x-5}{-3} \end{gathered}[/tex]
We are asked to determine the composite function:
[tex]g(f(x))[/tex]
To do that we will replace as the value of "x" in g(x) the function f(x), like this:
[tex]g(f(x))=\frac{(-3x+5)-5}{-3}[/tex]
Therefore, the numerator of the composite function is:
[tex]\text{ numerator g(f(x))=-3x+5-5}[/tex]
And the denominator is:
[tex]\text{ denominator g(f(x))=-3}[/tex]
Now we simplify the fraction, first by canceling out the 5:
[tex]g(f(x))=\frac{-3x}{-3}[/tex]
Now we cancel out the -3:
[tex]g(f(x))=x[/tex]
Since the composite function is "x" this means that the functions are inverses of each other.