Let's use the rules of priority: first of all, parenthesis. The expression in parenthesis is 12-8, which evaluates to 4, so the expression becomes

Next, exponents. The only exponent is
, which evaluates to 9. The expression becomes

Now we're left with sum/subtractions and multiplications/divisions only. We must perform multiplications/divisions first, in the order in which they appear. So, first of all, we must divide 4 by 2, which evaluates to 2. Let's update the expression:

Now it's time for the multiplication: 2 times 4 is 8, so we have

We're left with sums only. We can perform them in any order, since the sum is commutative. Let's sum the terms as they appear: first we put together 7 and 9 to get 16:

And finally give the answer of 24