what is the domain and range of the relation shown at the right

So the domain is the list of x values that are possible on a line. Looking at this graph, since the only x values that are possible on the line are greater than or equal to 0, the domain is x ≥ 0.
Next, the range is the list of y values that are possible on a line. Looking at this graph, since this line extends both directions vertically, the range is all real numbers.