To solve the problem, we start with \( (x + 5)^2 \) and then subtract it from 1.
First, we need to expand \( (x + 5)^2 \):
\[ (x + 5)^2 = x^2 + 2 \cdot x \cdot 5 + 5^2 = x^2 + 10x + 25 \]
Next, we subtract \( (x + 5)^2 \) from 1:
\[ 1 - (x^2 + 10x + 25) \]
Distributing the negative sign:
\[ 1 - x^2 - 10x - 25 \]
Now, we combine like terms:
\[ 1 - 25 - x^2 - 10x = -x^2 - 10x - 24 \]
Rearranging to write it in standard form, we get:
\[ -x^2 - 10x - 24 \]
So, the final answer is:
\[ -x^2 - 10x - 24 \]