2 z + z - 4
z^2 + z - 4
/ ____\ / ____\ | 1 \/ 17 | | 1 \/ 17 | |x + - - ------|*|x + - + ------| \ 2 2 / \ 2 2 /
(x + 1/2 - sqrt(17)/2)*(x + 1/2 + sqrt(17)/2)
2 -4 + z + z
-4 + z + z^2
-4.0 + z + z^2
-4 + z*(1 + z)