Answer:
n(A) = 7
Step-by-step explanation:
Let set A be A = {a,b,c}
We can say n(A) = 3
So basically n(A) means the "number of elements (unique) in set A"
They have to be unique.
For this problem, set A is:
A = {-3,-1,1,3,5,7,9}
If we count, there are 7 unique elements in this set. Thus:
n(A) = 7
