By definition:
- If a system has at least one solution, it's said to be consistent.
- If a system has exactly one solution, it's independent.
- If a system has infinite solutions, it's dependent
- If a system has no solutions, it's inconsistent.
Your system has exactly one solution (the two lines represent the two equations, and the point where they meet is the solution of the system), and so it is consistent, and in particular independent.