Answer:
a=(z-2)/2
Step-by-step explanation:
You need to isolate your "a" variable so first you want to subtract 2 from both sides, leaving you with:
z-2=2a
then you want to divide by 2 on both sides to isolate your "a" variable which would leave you with
a=[tex]\frac{(z-2)}{2}[/tex]
