Find the domain: { (2, 1), (6, 4), (7, 7), (7, 10) }

The answers is:

D={2,6,7}

You know that it is the domain because it is at the beginning of the parenthesis and is always x.

(x, y) if you were looking for y you would be looking for the second number in the parenthesis and that is know as range.

2, 6, and 7 are the domain because they are in the "x" spot