The expression you provided is $-(x + 3)$. This represents the negative of the quantity $(x + 3)$, which can be simplified by distributing the negative sign:

$-(x + 3) = -x - 3$

So, the simplified expression is $-x - 3$.

Do you want more details or have any questions?

Here are 5 related questions:

1. What happens if we add another term to $-(x + 3)$?
2. How would you solve $-(x + 3) = 0$?
3. Can you factor out the negative sign in a more complex expression?
4. What is the value of $-(x + 3)$ when $x = 2$?
5. How does this expression change if the exponent is involved?

Tip: Always distribute a negative sign carefully to all terms inside parentheses.