Remember the rule BIDMAS (Brackets, Indicies, Division, Multiplication, Addition, Subtraction)
Inside the brackets we have: 12 - 32 and again need to remember BIDMAS. The next item to consider is the Indicies. 32 = 9, so inside the brackets we have 12 - 9 = 3.
Go back to outside the brackets and we have 44 - (3)2, again consider the indicies first and 32 = 9. So we now have 44 - 9. What is 44 - 9? Try 44 - 4 first = 40. Now we still have 5 left to minius, so 40 - 5 = 35 and 35 is the final answer.