Answer
$\text{Domain:}\;\{-7,-5,-2,0\}$
$\text{Range:}\;\{-1,0,2,3\}$
$\text{Yes, this relation is a function.}$
Work Step by Step
The domain of a relation is the set of $x$ values for that function. In this relation, the set of $x$ values is $\{-7,-5,-2,0\}$. The range of a relation is the set of $y$ values for that relation. In this relation the set of $y$ values is $\{-1,0,2,3\}$. A relation is a function if and only if each $x$ value has only one unique $y$ value. Since there are not elements of the domain that are repeated with different elements of the range, this relation is a function.