Give the domain and range of the relations

Directions : Give the domain and range of the relations

{(1, 4), (3, 4), (7, 4), (-9, 4), (-5, 4)}

please explain how you got the answer/steps if you can, thanks

d=-9,-5,1,3,7
r=4

The domain is the x values. The range is the y values. If a number repeats itself you only say it once.