Because you have to go in the order of PEMDAS, parenthesis, exponents, multiplication, division, addition, and subtraction. From what you are saying, 'why you must simplify 3 to the second power first' it seems that you have no parenthesis, so you move onto what is next, which is exponents, in this case, 3 to the power of two.
Answer:

Step-by-step explanation:
Given
P(4,3)
Required
Solve
Using permutation formula;

This implies that





Answer:
-8 and 9
Step-by-step explanation:
-8 x 9 = -72
and -8 + 9 = 1
435 divided by 810 is 1.862068966. not rounded.
It is in the hundrethds place