Answer:
We see that the equation: x^2 - 4x + 4 is a perfect square trinomial as it is in the form of a^2 + 2ab + b^2, meaning that it is the square of a binomial. In this case, we see that we can multiply (x-2) with itself to obtain x^2 - 4x +4.
So the factored form is : (x-2)^2, or (x-2)(x-2)
We can check this by multiplying this out, and we obtain the same trinomial.
x^2-2x-2x+4
x^2-4x+4
Let me know if this helps!