[tex]12 - t = 16[/tex]
Add t to both sides!
[tex]12 - t +t = 16+t[/tex]
t will cancel out on the left hand side. We will be left with:
[tex]12 = 16+t[/tex]
Subtract 16 on both sides!
[tex]12 -16 = 16 + t -16[/tex]
16 will cancel out on the right hand side. We will be left with:
[tex]t = 12-16\\\\\boxed{\bf{t=-4}}[/tex]
Your final answer is t = -4.