Expand the left hand side using distributive property:
[tex]10x-50=80[/tex]Add 50 to both sides:
[tex]\begin{gathered} 10x-50+50=80+50 \\ 10x=130 \end{gathered}[/tex]Divide both sides by 10:
[tex]\begin{gathered} x=\frac{130}{10} \\ x=13 \end{gathered}[/tex]Answer:
x = 13
