Respuesta :

First multiply all terms by z
8-z^2=4z

Then order into standard form
-z^2-4z+8=0

Multiply the equation by -1
z^2+4z-8=0

Plug into quadratic equation
-4±√16-4(-8)
-4±√48

(-4±4√3)/2
-2±2√3

Final answer: z=-2± 2√3