1. **State the problem:**
We are given two functions:
$$f(x) = 5x - 6, \quad g(x) = x + 8$$
We need to find the following combined functions:
- $f + g$
- $f - g$
- $fg$
- $\frac{f}{g}$
and determine the domain of each.
2. **Formulas and rules:**
- Sum: $(f+g)(x) = f(x) + g(x)$
- Difference: $(f-g)(x) = f(x) - g(x)$
- Product: $(fg)(x) = f(x) \cdot g(x)$
- Quotient: $\left(\frac{f}{g}\right)(x) = \frac{f(x)}{g(x)}$, domain excludes points where $g(x) = 0$
3. **Calculate each combined function:**
- Sum:
$$(f+g)(x) = (5x - 6) + (x + 8) = 5x - 6 + x + 8 = 6x + 2$$
- Difference:
$$(f-g)(x) = (5x - 6) - (x + 8) = 5x - 6 - x - 8 = 4x - 14$$
- Product:
$$(fg)(x) = (5x - 6)(x + 8) = 5x \cdot x + 5x \cdot 8 - 6 \cdot x - 6 \cdot 8 = 5x^2 + 40x - 6x - 48 = 5x^2 + 34x - 48$$
- Quotient:
$$\left(\frac{f}{g}\right)(x) = \frac{5x - 6}{x + 8}$$
4. **Determine domains:**
- For $f+g$, $f-g$, and $fg$, both $f$ and $g$ are polynomials defined for all real numbers, so domain is $\mathbb{R}$.
- For $\frac{f}{g}$, denominator $g(x) = x + 8 \neq 0$, so domain excludes $x = -8$.
5. **Final answers:**
- $$(f+g)(x) = 6x + 2, \quad \text{domain: } (-\infty, \infty)$$
- $$(f-g)(x) = 4x - 14, \quad \text{domain: } (-\infty, \infty)$$
- $$(fg)(x) = 5x^2 + 34x - 48, \quad \text{domain: } (-\infty, \infty)$$
- $$\left(\frac{f}{g}\right)(x) = \frac{5x - 6}{x + 8}, \quad \text{domain: } (-\infty, -8) \cup (-8, \infty)$$
Function Operations F1Cf6E
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