Find the value of n such that x^2 - 10x + n is a perfect square trinomial.

To find the value of n such that x^2 - 10x + n is a perfect square trinomial, we need to determine the value of n such that the trinomial can be factored into the form (x - a)^2, where a is a constant.

Expanding (x - a)^2, we get x^2 - 2ax + a^2.

Comparing this with x^2 - 10x + n, we can set up the following equations:

-2a = -10 (comparing the coefficients of x)
a^2 = n (comparing the constant terms)

From the first equation, we can solve for a:

-2a = -10
a = 5

Substituting this value of a into the second equation, we can solve for n:

a^2 = n
5^2 = n
25 = n

Therefore, the value of n such that the trinomial x^2 - 10x + n is a perfect square trinomial is 25.