What is a direct proportional relationship?

it’s a special relationship between two variables. as one increases or decreases, the other one does the same.

Step-by-step explanation:

sample answer: you can determine whether each element of the domain is paired with exactly one element of the range. for example, if given a graph, you could use the vertical line test; if a vertical line intersects the graph more than once, then the relation that the graph represents is not a function.