1. **Stating the problem:**
Solve the system of linear equations for each set (a), (b), and (c).
2. **Method:**
We will use the substitution or elimination method to find the values of $x$ and $y$.
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### a) System:
$$\begin{cases}-x + 3y = -5 \\ 2x - 5y = 8\end{cases}$$
3. From the first equation, express $x$:
$$-x + 3y = -5 \implies x = 3y + 5$$
4. Substitute $x$ into the second equation:
$$2(3y + 5) - 5y = 8$$
$$6y + 10 - 5y = 8$$
$$y + 10 = 8$$
$$y = 8 - 10 = -2$$
5. Substitute $y = -2$ back into $x = 3y + 5$:
$$x = 3(-2) + 5 = -6 + 5 = -1$$
**Solution for (a):** $x = -1$, $y = -2$
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### b) System:
$$\begin{cases}x - 2y = -9 \\ \frac{1}{4}x - \frac{1}{2}y = 10\end{cases}$$
6. Multiply the second equation by 4 to clear fractions:
$$x - 2y = 40$$
7. Now we have:
$$\begin{cases}x - 2y = -9 \\ x - 2y = 40\end{cases}$$
8. These two equations contradict each other (same left side, different right side), so there is **no solution**.
**Solution for (b):** No solution (the system is inconsistent).
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### c) System:
$$\begin{cases}5x + 10y = 25 \\ 15x + 30y = 75\end{cases}$$
9. Notice the second equation is exactly 3 times the first:
$$15x + 30y = 3(5x + 10y) = 3 \times 25 = 75$$
10. This means the two equations represent the same line, so there are infinitely many solutions.
**Solution for (c):** Infinitely many solutions (dependent system).
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**Final answers:**
- (a) $x = -1$, $y = -2$
- (b) No solution
- (c) Infinitely many solutions
Solve Systems 5D07Ca
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