The domain are the input values which are also the values of x
The range are the corresponding output values which are also the values of y
Looking at the given values, the domain are 1, - 2, - 1, 1.
Their sum is 1 + - 2 + - 1 + 1 = 1 - 2 - 1 + 1
The sum of the domain is - 1
the range are - 2, 0, 2, 3.
Their sum is - 2 + 0 + 2 + 3
The sum of the range is 3