x^3-6x^2 + 12x-8.

The answer is (x-2)^3. How do i do this problem?

Synthetic division is one way to find your factors.

Here's how this one works out:

2| 1 -6 12 8
..... 2 -8 8
.. 1 -4 4 0

Therefore: (x - 2)(x^2 - 4x + 4)
Factors of (x^2 - 4x + 4) are (x - 2)(x - 2)

Factors are: (x - 2)(x - 2)(x - 2) or (x - 2)^3

I hope this will help.