if car is worth $40,000 and then ten years later it is worth $24,000 express the cars value in dollars as a function of time

The domain of the following relation: r: {(3, 5), (8, 6), (2, 1), (8, 6)} is (1 point) no domain exists {1, 5, 6} {3, 8, 2, 8} {2, 3, 8}