When is subtraction always the first operation done in an expression?

Answer:
When it is in parentheses.
Step-by-step explanation:
In PEMDAS, first is always parentheses, no matter what operation.
If it is subtraction, do that first.
hope this helped!
Answer:
the 3rd one
Step-by-step explanation:
this is only true when it is in perenthisis because when you do PEDMAS you go in that order. P (perenthisis) beng first. so TECHNECLY perenthisis is first, but the first actual MATH PROBLEM being done is subtraction.