To solve the system of equations by graphing, let's look at the equations:
- \( y = 5x + 3 \)
- \( y = 5x + 15 \)
Both equations have the same slope (5), but different y-intercepts (3 and 15).
Due to having the same slope but different y-intercepts, these lines are parallel. Parallel lines never intersect, which means there are no points (x, y) that satisfy both equations at the same time.
Therefore, the conclusion is:
No solutions.