Answer:
x < 7
Explanation:
the domain is the number range or interval of x the function is defined for to generate a y-value.
the graph shows that the y-values continue with x-values to the right up to but not including 7 (the empty dot says "excluding"). and with x- values to the left to negative infinity.
x=-1 is not a problem, because while for the left part of the function it is not included, but for the right part it is.
so, it is fully defined for all x < 7.