Answer:
d = 7.2
General Formulas and Concepts:
Pre-Algebra
Order of Operations: BPEMDAS 
- Brackets 
- Parenthesis 
- Exponents 
- Multiplication 
- Division 
- Addition 
- Subtraction 
Algebra II
- Distance Formula: 
  
Explanation:
Step 1: Define
Boat A(3.1, -1)
Boat B(-4.1, -1)
Step 2: Find distance d
Simply plug in the 2 coordinates into the distance formula to find distance d.
- Substitute [DF]: 
  
- Subtract/Add: 
  
- Exponents: 
  
- Evaluate: 
 