Explanation:
For you to represent a multiple system on a graph, first you need to know that it consists of different variables which are dependent and independent variables.
The independent variables are constant and the dependent variables changes with respect to the data presented.
The X and Y axis of a graph houses this variables depending on how the data is analysed and it is plotted one by one until all the data is being represented in the graph. For multiple systems, you will get more then one line either linear, sinusoidal...e.t.c but with reference to a common independent variable.
Multiple representations of a system be graphed an their key features can be compared when the different variables a represented in same graph at same time making reference to the graph.