Answer:
i think but I am not sure so maybe ask somebody else but I think it is A.
Step-by-step explanation:
I just think it is
Answer:15
Step-by-step explanation:
Given
Craftsman sell 10 Jewelry set for $500 each
For each additional set he will decrease the price by $ 25
Suppose he sells n set over 10 set
Earning
Earning 

differentiate to get the maximum value

Equate
to get maximum value



Thus must sell 5 extra set to maximize its earnings.
Answer:
Green and blue is your answer.
:)
Z-4/9-1/3=5/9
z-4 =5/9(9-1/3)
z-4 =4.414814815
z =8.814