Hello there.
To get the answer, let's follow the order of operations and that is
PEMDAS.
Now let's start.
First is P (Parenthesis)
9+18-(8÷4)x12
= 9+18-2x12
Second is E (Exponent)
There are no exponents so we'll just skip this.
Third is M (Multiplication)
9+18-2x12
= 9+18-24
Fourth is D (Division)
There are no divisions right now. So we'll just skip this.
Fifth is A (Addition)
9+18-24
= 27-24
Sixth is S (Subtraction)
27-24
= 3
So, as we follow the order of operations we finally got the answer and that is 3.
Hope it helped! I'm trying my best you know.