System Consistency 7E91F8
1. **State the problem:** Determine if the system of equations
$$\begin{cases} x + 2y = 8 \\ x - y = 4 \end{cases}$$
is consistent or inconsistent and dependent or independent.
2. **Recall definitions:**
- A system is **consistent** if it has at least one solution.
- It is **inconsistent** if it has no solutions.
- It is **dependent** if the equations represent the same line (infinitely many solutions).
- It is **independent** if the equations represent different lines that intersect at exactly one point.
3. **Solve the system:**
From the second equation, express $x$:
$$x = y + 4$$
Substitute into the first equation:
$$y + 4 + 2y = 8$$
Simplify:
$$3y + 4 = 8$$
$$3y = 4$$
$$y = \frac{4}{3}$$
Find $x$:
$$x = \frac{4}{3} + 4 = \frac{4}{3} + \frac{12}{3} = \frac{16}{3}$$
4. **Interpretation:**
The system has a unique solution $\left(\frac{16}{3}, \frac{4}{3}\right)$, so it is **consistent** and **independent**.
**Final answer:** The system is consistent and independent.