To solve the inequality \( f - 4 \leq -3 \), you need to isolate \( f \) by adding 4 to both sides.
So, you would add 4 to each side of the inequality.
Therefore, you would enter 4 as your response.
The completed inequality would then be:
\[ f - 4 + 4 \leq -3 + 4 \]
Which simplifies to:
\[ f \leq 1 \]