Answer :

Answer:

s - t = -1

Step-by-step explanation:

Set up equation.

s + 3t  = t + 3s + 2

Move variables to one side.

s + 3t - t  - 3s = -2

-2s + 2t = 2

Divide by -2.

s - t = -1

Therefore, s - t equals -1.