I notice there is an x^2 but not a z^2.

So i know my answer will be like this:

(Something x +or- z) (something x +or- 3)

I need a 3x so it will be

(x +or- z) (x +or- 3)

I need a positive 4x^2 and a negative 4xz so it would be

(x-z) (4x-3)

"Find value" isn't clear to me, did you mean when x= -2 and z = -3?