Can someone please help me with this? I can’t understand it.

The domain of a relation or a function is the set of all possible values for an input in that relation/function.
Notice from the graph that the function runs for x-values from -1 to 5, inclusive.
Hence, the domain is:
[tex]\lbrack-1,5\rbrack[/tex]The range of a relation or function is the set of all possible values that can be the result of a relation or function.
These are the range of y-values of the graph, which is from -2 to 4, inclusive.
Hence, the range is:
[tex]\lbrack-2,4\rbrack[/tex]The domain is [-1,5], the range is [-2,4].
Re-write using compound inequality:
[tex]\begin{gathered} \text{Domain: }-1\le x\le5 \\ \text{Range: }-2\le y\le4 \end{gathered}[/tex]