D. They have the same slope, and the same y-intercept so they have infinitely many solutions.
Step-by-step explanation:
Graphing these lines shows that both lines are the exact same line, and cannot have a point of intersection. Solving the equations shows you a value that is ultimately always correct; such as 0=0. This can be used as proof that "They have the same slope, and the same y-intercept so they have infinitely many solutions" because either equation can be rearranged to equal the other.
