Answer:
The last graph, where the functions intersect at only one point.
Step-by-step explanation:
A system of equations with only one solution is the one that in some point the solutions of each ecuation is exactly the same. In the graphs 1 and 3, where the equations does not intersect each other, the system of equations have no solution. In the second graph, the equations intersect 2 times, so the system of equations have 2 solutions.
