Help?? I seriously don’t understand?

Answer:
A. 30
Step-by-step explanation:
The answer is 30 because x= 12 so that means that x-2 is 10 because x is 12, so since its in parenthesizes that means you do that part of the problem first. So, after we have 10 we will do times 3 since the 3 is also there and it says what is the value. So, therefore the answer is A. 30.