It’s asking me to solve for z...Can someone please explain how I can workout this problem?

Answer:
12°
Step-by-step explanation:
Step 1:
7z + 6° = 90° Def. of Right Angle
Step 2:
7z = 84° Subtract 6° on both sides
Step 3:
z = 84° ÷ 7 Divide
Answer:
z = 12°
Hope This Helps :)