Answer:
I think it is by multiplying by 2.
Step-by-step explanation:
Even if it depends on the x, the constant of proportionality just goes by the multiple of 2 as you can see on the graph.
For example, the point that's on ( 2, y) on the graph is the start of it's proportional relationship that is on the line. Here is an example of how it is proportional:
hope it helps in a way:)
