The given equation is
[tex]-px+r=-8x-2[/tex]First, we add 8x on each side
[tex]\begin{gathered} 8x-px+r=-8x+8x-2 \\ x(8-p)+r=-2 \end{gathered}[/tex]Then, we subtract r from each side
[tex]\begin{gathered} x(8-p)+r-r=-2-r \\ x(8-p)=-2-r \end{gathered}[/tex]At last, we divide the equation by 8-p
[tex]\begin{gathered} \frac{x(8-p)}{8-p}=\frac{-2-r}{8-p} \\ x=\frac{-2-r}{8-p} \end{gathered}[/tex]