Answer:
The answer to your problem should be 2
x^2 - 6x + 8 = x^2 - 2x - 4x + 8 = x(x-2) - 4(x-2) = (x-4) (x-2)
x - 4 = 0 => x = 4
x - 2 = 0 => x = 2
