Answer:
The correct answer is 21.
Step-by-step explanation:
To solve this problem, we simply substitute 3 for a in the expression.
Given the expression,
a^2 + 12
we should replace "a" with 3, as denoted by the problem, giving us:
(3)^2 + 12
Now, we simplify using the order of operations. PEMDAS tells us that we should simplify what is in the parentheses first because it has an exponent.
9 + 12
Now, we can just add the two remaining terms together, giving us:
21
Therefore, the answer is 21.
Hope this helps!
