Answer:
z = 1
Explanation:
-z + 7 = 6
-7 -7
-1
So, basically add -7 on both side (or the kcf method) which cancels out on on the right side but makes -1 on then notice how the -z/-1 = a positive because a negative divided by a negative is a positive so its positive one.
How to check?
just replace -z with -1 and put -1 + 7 = 6 which makes this answer correct.