The given equation is
[tex]3z-19=173[/tex]First, we add 19 on each side
[tex]\begin{gathered} 3z-19+19=173+19 \\ 3z=192 \end{gathered}[/tex]Then, we divide the equation by 3
[tex]\begin{gathered} \frac{3z}{3}=\frac{192}{3} \\ z=64 \end{gathered}[/tex]