I think that this is the x-intercept method:
First of all, we set y=x^3-6x^2+11x-6.
To find x, we need to let y=0. (y is also equals to f(x))
f(x)=x^3-6x^2+11x-6
In order to make f(x)=0, what does x have to be?
f(1)=0
So then we divide x^3-6x^2+11x-6 by x-1. Why? Because that will not give us a remainder.
(x^3-6x^2+11x-6)/(x-1) = x^2-5x+6
Now, we need to factorize it.
x^2-5x+6 = (x-2)(x-3)
So x=2,3