Answer:
a)

b)
First of all, I divided both sides by 2, simplified, and then subtracted z from both sides. Then, I got the final result for 'a'.
Explanation:
a) Solving the equation
Given the expression

Divide both sides by 2

simplify

subtract z from both sides


Thus, the value of a:

b) Work Process
First of all, I divided both sides by 2, simplified, and then subtracted z from both sides. Then, I got the final result for 'a'.