The function is
\[
f(x) = -3x - 3.
\]
Given range values are $\{3, -6, -9, -18\}$. For each range value $y$, solve for $x$:
\[
y = -3x - 3 \implies x = \frac{-3 - y}{3}.
\]
Calculate $x$ for each $y$:
\[
y = 3: x = \frac{-3 - 3}{3} = \frac{-6}{3} = -2,
\]
\[
y = -6: x = \frac{-3 - (-6)}{3} = \frac{-3 + 6}{3} = \frac{3}{3} = 1,
\]
\[
y = -9: x = \frac{-3 - (-9)}{3} = \frac{-3 + 9}{3} = \frac{6}{3} = 2,
\]
\[
y = -18: x = \frac{-3 - (-18)}{3} = \frac{-3 + 18}{3} = \frac{15}{3} = 5.
\]
Domain values that produce the range are $\{-2, 1, 2, 5\}$. The value $-1$ is not in the domain because it does not produce any $y$ in the range.