Answer:
12
Step-by-step explanation:
[tex]\dfrac{7}{9}z-18+\dfrac{1}{3}z\\\\\text{Substitute}\ z=27\\\\\dfrac{7}{9\!\!\!\!\diagup_1}\cdot27\!\!\!\!\!\diagup^3-18+\dfrac{1}{3\!\!\!\!\diagup_1}\cdot27\!\!\!\!\!\diagup^9=(7)(3)-18+(1)(9)\\\\=21-18+9=12[/tex]
