There are 5 yellow pens 6 blue pens 9 green pens she picks 1 at random and does not replace it then she picks another pen

x= 3^y

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.