x=-9
Explanation
[tex]\frac{1}{3}x-9=-12[/tex]
Step 1
add 9 in both sides
[tex]\begin{gathered} \frac{1}{3}x-9=-12 \\ \frac{1}{3}x-9+9=-12+9 \\ \frac{1}{3}x=-3 \end{gathered}[/tex]Step 2
multiply both sides by 3
[tex]\begin{gathered} \frac{1}{3}x=-3 \\ \frac{1}{3}x\cdot3=-3\cdot3 \\ x=-9 \end{gathered}[/tex]I hope this helps you