Answer:
m = -1/2
General Formulas and Concepts:
Pre-Algebra
Order of Operations: BPEMDAS 
- Brackets 
- Parenthesis 
- Exponents 
- Multiplication 
- Division 
- Addition 
- Subtraction 
Equality Properties
Explanation:
Step 1: Define
9m - m + 3 = -2(m + 1)
Step 2: Solve for m
- Combine like terms: 8m + 3 = -2(m + 1)
- Distribute -2: 8m + 3 = -2m - 2
- Add 2m on both sides: 10m + 3 = -2
- Isolate m term: 10m = -5
- Isolate m: m = -1/2