Final answer:
The range of the given relation x≤0, all real numbers, y≤0 is y ≤ 0.
Step-by-step explanation:
The range of a relation represents the set of all possible y-values or outputs of the relation. In this case, the given relation states that x ≤ 0 and y ≤ 0 for all real numbers. This means that any value of x that is less than or equal to 0 will have a corresponding y-value that is also less than or equal to 0. Therefore, the range of the relation is y ≤ 0.