can you do the check part too? so i can understand. thank you!

12 is dividing on the left, then it will multiply on the right.
[tex]\begin{gathered} 9+t=(-3)\cdot12 \\ 9+t=-36 \end{gathered}[/tex]9 is adding on the left, then it will subtract on the right
t = -36 - 9
t = -45
To check the answer, replace the value found into the original equation, as follows:
[tex]\frac{9-45}{12}=\frac{-36}{12}=-3[/tex]