2 x - 8*x - 16
x^2 - 8*x - 16
/ ___\ / ___\ \x + -4 + 4*\/ 2 /*\x + -4 - 4*\/ 2 /
(x - 4 + 4*sqrt(2))*(x - 4 - 4*sqrt(2))
2 -16 + x - 8*x
-16 + x^2 - 8*x
-16.0 + x^2 - 8.0*x
-16 + x*(-8 + x)