Answer:
24
Explanation:
The most important thing to note here is that there are no parentheses defining what to do when.
Therefore, we have to use order of operations - PEMDAS, to find the expression's value.
PEMDAS states that the order you go in is:
1. Parentheses
2. Exponents
3. Multiplication/Division
4. Addition/Subtraction

There are no parentheses, so first we have to solve the exponent.

Now we have to multiply.

And now subtract.

Hope this helped!