Answer:
Explanation:
We are to Formulate the question given as a Linear Programming problem with the objective of maximizing profit.
From the question; 
Kings will sell each bracelet for $400 and it costs them $150 to make it.
This implies that; King will net a profit on $250 on each bracelet made with 2 rubies, 3 diamonds, and 4 emeralds :
Also;
 Kings will sell each necklace for $700 and it costs them $200 to make it
i.e King will net a profit of $500 on each necklace made with 5 rubies, 7 diamonds, and 3 emeralds. 
Now; let's assume that :
 be the no of bracelets made ; &
 be the no of bracelets made ; &
 be the no of necklaces made
 be the no of necklaces made 
 
 (Objective Function)
 (Objective Function) 
 
Subject to :
 
 ← 625 (rubies)
 ← 625 (rubies) 
 
 ← 800 ( diamonds)
 ← 800 ( diamonds) 
 
 ← 700 (Emeralds)
 ← 700 (Emeralds) 
 
 ⇒ 0 (non-negativity)
 ⇒ 0 (non-negativity) 
 
 ⇒ 0 (non negativity)
 ⇒ 0 (non negativity)