2z/3-7=-9 what is z?

Multiply both sides by 3
2z−21=−27
Add 21 to both sides
2z=−27+21
Simplify −27+21 to −6
2z=−6
Divide both sides by 2
z=−6
Simplify $$\frac{6}{2}$$ to 3
z=−3