The equation that would be added to the graph line that will make the system of equations has infinitely many solutions, will be the equation that has the same graph has the graph provided on the graph sheet.
Thus, to find the equation, we will need to plot all the equations and find the graph that corresponds to the graph on the graph sheet.
First equation
The graph of the equation above is shown below
For the second equation
The graph of the second equation is
For the third equation
The graph of the third equation is
For the fourth equation
The graph of the fourth equation is
Hence, the graphs above, the equation that aligns with the graph provided on the graph sheet, that will make the system of equation has infinitely many solution is