Answer :

To find the domain of the composite function [tex]\( (f \circ g)(x) \)[/tex], follow these steps:

1. Express the Composite Function:

Given:
[tex]\[ f(x) = \frac{x-3}{x} \][/tex]
[tex]\[ g(x) = 5x - 4 \][/tex]

The composite function [tex]\( (f \circ g)(x) \)[/tex] is found by substituting [tex]\( g(x) \)[/tex] into [tex]\( f \)[/tex]:
[tex]\[ (f \circ g)(x) = f(g(x)) = f(5x - 4) \][/tex]

Substituting [tex]\( 5x - 4 \)[/tex] for [tex]\( x \)[/tex] in [tex]\( f \)[/tex]:
[tex]\[ f(5x - 4) = \frac{(5x - 4) - 3}{5x - 4} = \frac{5x - 7}{5x - 4} \][/tex]

2. Determine the Domain of [tex]\( g(x) \)[/tex]:

The function [tex]\( g(x) = 5x - 4 \)[/tex] is defined for all real numbers, so the domain of [tex]\( g(x) \)[/tex] is:
[tex]\[ (-\infty, \infty) \][/tex]

3. Find the Domain Restrictions Imposed by [tex]\( f(x) \)[/tex]:

The function [tex]\( f(x) = \frac{x-3}{x} \)[/tex] requires that the denominator [tex]\( x \neq 0 \)[/tex]. When substituting [tex]\( g(x) \)[/tex] into [tex]\( f(x) \)[/tex], we require:
[tex]\[ 5x - 4 \neq 0 \][/tex]

Solve for [tex]\( x \)[/tex]:
[tex]\[ 5x - 4 = 0 \implies x = \frac{4}{5} \][/tex]

Therefore, [tex]\( x \)[/tex] cannot be [tex]\( \frac{4}{5} \)[/tex] because it would make the denominator zero in the composite function.

4. Combine the Domain Restrictions:

The domain of [tex]\( g(x) \)[/tex] is all real numbers, but since [tex]\( 5x - 4 \)[/tex] cannot equal zero, we exclude [tex]\( x = \frac{4}{5} \)[/tex] from the domain. Hence, the domain of [tex]\( (f \circ g)(x) \)[/tex] is:
[tex]\[ (-\infty, \frac{4}{5}) \cup (\frac{4}{5}, \infty) \][/tex]

Thus, the domain of the composite function [tex]\( (f \circ g)(x) \)[/tex] is:
[tex]\[ \boxed{(-\infty, \frac{4}{5}) \cup (\frac{4}{5}, \infty)} \][/tex]