\(x^2-6x+8=x^2-2x-4x+8=x(x-2)-4(x-2)=(x-2)(x-4)\)
\(x^2-6x+8=x^2-2x-4x+8=\left(x^2-2x\right)-\left(4x-8\right)=x\left(x-2\right)-4\left(x-2\right)=\left(x-2\right)\left(x-4\right)\)
x² - 6x + 8
= x² - 2x - 4x + 8
= (x² - 2x) - (4x - 8)
= x(x - 2) - 4(x - 2)
= (x - 2)(x - 4)