To express \((x - 5)^2\) as a trinomial in standard form, we can expand the expression.
First, recall the formula for squaring a binomial:
\[ (a - b)^2 = a^2 - 2ab + b^2 \]
In our case, \(a = x\) and \(b = 5\). Now, we will apply the formula:
\[ (x - 5)^2 = x^2 - 2(5)(x) + 5^2 \]
Calculating each term:
- \(x^2\) remains \(x^2\)
- \(-2(5)(x)\) becomes \(-10x\)
- \(5^2\) becomes \(25\)
So, we can combine these to get:
\[ (x - 5)^2 = x^2 - 10x + 25 \]
Thus, the trinomial in standard form is:
\[ \boxed{x^2 - 10x + 25} \]