To solve the equation \( x + 11 = -17 \) for \( x \), you need to isolate \( x \).
To do this, you should subtract 11 from both sides of the equation. This will give you:
\[ x + 11 - 11 = -17 - 11 \]
which simplifies to:
\[ x = -28 \]
So, the correct response is subtract 11.