Linear Systems 4624C5
1. **State the problem:** We have two systems of linear equations and need to determine the nature of their solutions (no solution, unique solution, or infinitely many solutions).
2. **System A:**
$$y = 7x + 8$$
$$y = 7x + 5$$
These are two lines with the same slope ($7$) but different y-intercepts ($8$ and $5$).
3. **Rule:** If two lines have the same slope but different y-intercepts, they are parallel and do not intersect.
4. **Conclusion for System A:** No solution because the lines are parallel.
5. **System B:**
$$-x - 3y = 1$$
$$x + 3y = -1$$
Rewrite the second equation:
$$x + 3y = -1$$
Multiply the first equation by $-1$:
$$x + 3y = -1$$
6. **Observation:** Both equations are identical after simplification, meaning they represent the same line.
7. **Conclusion for System B:** Infinitely many solutions because both equations represent the same line.
**Final answers:**
- System A: The system has no solution.
- System B: The system has infinitely many solutions.