Answer
domain: $\left\{-3\right\}$
range: $\left\{-\infty, +\infty\right\}$
Refer to the graph below.
Work Step by Step
Solve for $x$ to obtain:
$3+x=0
\\3+x-3=0-3
\\x=-3$
This means the given equation is equivalent to $x=-3$.
RECALL:
The line $x=a$, where $a$ is a real number::
(a) is vertical. All points on this line have an x-coordinate of $a$;
(b) has the set of real numbers as its range; and
(c) has a domain of $\left\{a\right\}$
Thus, the graph of the equation $x=-3$ is a vertical line.
All points on the line have an x-coordinate of $-3$.
The domain is $\left\{-3\right\}$.
The range is $\left\{-\infty, +\infty\right\}$.
The line contains the points $(-3, 0)$ and $(-3, 3)$.
Plot the points above and connect them using a line.
(Refer to the graph in the answer part above.)