Solve for x.

Let's solve the equation step by step.

Given the equation:

\[ 3(2x + 2) - x - 3 = -12 \]

1. Distribute the \(3\) to the terms inside the parentheses:

\[
3 \cdot 2x + 3 \cdot 2 - x - 3 = -12
\]

This simplifies to:

\[
6x + 6 - x - 3 = -12
\]

2. Combine like terms (combine \(6\) and \(-3\), and \(6x\) and \(-x\)):

\[
6x - x + 6 - 3 = -12
\]

This gives:

\[
5x + 3 = -12
\]

3. Now, isolate \(5x\) by subtracting \(3\) from both sides:

\[
5x = -12 - 3
\]

Which simplifies to:

\[
5x = -15
\]

4. Finally, divide both sides by \(5\):

\[
x = \frac{-15}{5}
\]

This simplifies to:

\[
x = -3
\]

So the solution is:

\[
\boxed{-3}
\]