1. **State the problem:** We are given two functions $f(x) = \frac{x+4}{x}$ and $g(x) = x+3$. We need to find the composition $(f \circ g)(x)$, which means $f(g(x))$, and then determine its domain.
2. **Recall the composition formula:** The composition $(f \circ g)(x)$ is defined as $f(g(x))$. This means we substitute $g(x)$ into $f$.
3. **Calculate $f(g(x))$:**
$$
(f \circ g)(x) = f(g(x)) = f(x+3) = \frac{(x+3)+4}{x+3} = \frac{x+7}{x+3}
$$
4. **Determine the domain:**
- The domain of $g(x) = x+3$ is all real numbers.
- The domain of $f(x) = \frac{x+4}{x}$ is all real numbers except $x \neq 0$ because division by zero is undefined.
- For $f(g(x))$, the input to $f$ is $g(x) = x+3$. So we must have $x+3 \neq 0$ to avoid division by zero.
5. **Domain of $(f \circ g)(x)$:**
$$
x+3 \neq 0 \implies x \neq -3
$$
6. **Final answer:**
$$(f \circ g)(x) = \frac{x+7}{x+3}, \quad \text{with domain } \{x \in \mathbb{R} : x \neq -3\}$$
Composition Domain 7Cae49
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