Answer:
(10, 1), (15, 1), (20, 13), (25, 7)
IS a function
Explanation:
The ordered pairs are (input, output). Essentially, the numbers in each ordered pair are the numbers at each end of an arrow. There are as many ordered pairs as there are arrows.
Working top-down on input values, the ordered pairs of this relation are ...
(10, 1), (15, 1), (20, 13), (25, 7)
None of the input values is repeated, so the relation is a function.