The domain of a list of points is all the x- values the function (or relation, they are the same words) can take.
In our case the domain is
[tex]D=\mleft\lbrace3,0,7\mright\rbrace[/tex]Similarly, the range of a list of points is all the possible y- values the relation can take; therefore, in our case the range is
[tex]R=\mleft\lbrace-5,7,1,5\mright\rbrace[/tex]