Answer:
The expression is equal to 12.
Explanation:

First of all, compute the parenthesis.
18 / 6 = 3
Now, replace 18/6 with 3 in our expression.


Next, compute the multiplication.
-12 * 3 = -36
Again, we'll replace that multiplication with negative 36:


Since subtracting a negative number is the same as adding a positive number:

Compute the addition:


Answer: The expression is equal to 12.