2 2 4*x - 9*z
4*x^2 - 9*z^2
/ 3*z\ / 3*z\ 1*|x + ---|*|x - ---| \ 2 / \ 2 /
(1*(x + 3*z/2))*(x - 3*z/2)
4.0*x^2 - 9.0*z^2
(-3*z + 2*x)*(2*x + 3*z)