2 z + 14*z + 4
z^2 + 14*z + 4
2 4 + z + 14*z
4 + z^2 + 14*z
/ ___\ / ___\ \x + 7 + 3*\/ 5 /*\x + 7 - 3*\/ 5 /
(x + 7 + 3*sqrt(5))*(x + 7 - 3*sqrt(5))
4.0 + z^2 + 14.0*z
4 + z*(14 + z)