Answer:
Step-by-step explanation:
[tex]20z-5-12z=10z+8\qquad\text{combine like terms}\\\\(20z-12z)-5=10z+8\\\\8z-5=10z+8\qquad\text{add 5 to both sides}\\\\8z=10z+13\qquad\text{subtract}\ 10z\ \text{from both sides}\\\\-2z=13\qquad\text{divide both sides by (-2)}\\\\z=-6.5[/tex]