Which of the following is a one-to-one functions?

A function f : X → Y is said to be one to one (or injective function), if the images of distinct elements of X under f are distinct, i.e., for every x1 , x2 ∈ X, f(x1 ) = f(x2 ) implies x1 = x2 . Otherwise, it is called many to one function.

x=30

step-by-step explanation:

table 3 represents a direct variation function. : )