Sofia used these steps to find the inverse function f. what step did she mess up on and why

Wrong step: 6
she should have, divided each side by 3
[tex]\begin{gathered} 8x-4=3y \\ \\ \frac{8x}{3}-\frac{4}{3}=\frac{3y}{3} \\ \\ \frac{8x-4}{3}=y \end{gathered}[/tex]