If #(w,x,y,z)means you square the product of all the terms, for all positive value of w,x,y, and z and #(1,2,3,z)=144, then z = ?

please explain how to do that

so just follow the instructions,

((1)(2)(3)z)^2 = 144

(6z)^2 = 144
36z^2 = 144
z^2 = 4
z = 2

Actually the wording of the question is flawed.
Terms are separated by addition and subraction, there is only one term here.
The correct wording should be :
If #(w,x,y,z)means you square the product of all the factors, for all positive ....