2 x - 6*x + 8
x^2 - 6*x + 8
(x - 2)*(x - 4)
2 8 + x - 6*x
8 + x^2 - 6*x
8.0 + x^2 - 6.0*x
8 + x*(-6 + x)
(-4 + x)*(-2 + x)