Use order of operations, or PEMDAS which stands for Parenthesis, Exponent, Division, Addition, and Subtraction.
Do those operations in that order. Can you try?
What will be the first thing you do here, according to PEMDAS?
Yes (my answer need to be greater than 20 characters long so...Ahhhhh). A way to help you is see it as 4.1 and 4.0 because the # after the 1 aren't that important
Answer:
(A)
Step-by-step explanation:
Given a set with "n" number of elements, the collection of all subsets of the set is referred to as the Power set of the given set.
To find the number of possible subsets of any set, we use the formula: 
Take for example the set: A={2,3,4)
A has 3 elements, therefore n=3
The number of possible subsets of A is: 
Answer: 20
Explanation: The equation is 175 - 15 (160) and then divide it by 8 (20)