Could you please solve it step by step with clear explanation? Please do not only write the answer. Explanation is very important.

' 1/ Question 1. (10 Marks) Find all the rst and second order partial derivatives for the following functions with two or three variables: 1) f(a:, y) = 5\"?!2 ii) g($, y, z) = 8w2y2z 3(CB + y + z)