To solve the quadratic equation \( x^2 + 10x + 25 = 0 \) using the perfect square trinomial pattern, we first recognize that the left-hand side can be factored.
The expression \( x^2 + 10x + 25 \) is a perfect square trinomial, and it can be factored as:
\[ (x + 5)^2 \]
So, we can rewrite the equation as:
\[ (x + 5)^2 = 0 \]
To solve for \( x \), we take the square root of both sides:
\[ x + 5 = 0 \]
Now, isolate \( x \):
\[ x = -5 \]
Thus, the solution is:
\[ x = -5 \]