Answer:
4
General Formulas and Concepts:
Pre-Algebra
Order of Operations: BPEMDAS 
- Brackets 
 - Parenthesis 
 - Exponents 
 - Multiplication 
 - Division 
 - Addition 
 - Subtraction 
 
Explanation:
Step 1: Define
a = 3, b = 5, c = 1
b - c
Step 2: Evaluate
- Substitute: 5 - 1
 - Subtract: 4