Answer:
-3i - 12
Step-by-step explanation:
Rearrange so all the constant terms are on on one side, then perform the calculation of that side. Then simply add the coefficient and variable to the whole puzzle also adding the subtraction symbol that dose not change throughout the process. Done! Hope this helps. Also the 3 turns negative because of the minus it would be - 3 when re arranged which makes it equivalent to negative 3.