5 2/3 would be 3 times 5 +2 think of it as starting the letter C from the bottom to the top multiply the bottom and middle add the top
If you do that you should get 17/3
The answer is A. I looked it up for you on an surface area calculator.
Distributive property because if you divide -5.2+(-8.4) by -1, you get -(5.2+8.4)
10P4 = 10! / (10-4)! = 10*9*8*7 = 5040
9C4 = 9! / 5! 4! = 9*8*7*6 / 4*3*2*1 = 126