Final answer:
When a system of two equations with two variables has infinitely many solutions, the graphs of these equations coincide, representing the same line.
Step-by-step explanation:
When a system of two equations with two variables has infinitely many solutions, it means that the two equations represent the same line. This means that the graphs of these equations coincide and are indistinguishable from each other. They have the same slope, intercept, and every point on one graph is also on the other graph.