Answer:
m = undef
General Formulas and Concepts:
Pre-Algebra
Order of Operations: BPEMDAS 
- Brackets 
- Parenthesis 
- Exponents 
- Multiplication 
- Division 
- Addition 
- Subtraction 
Algebra I
- Coordinates (x, y)
- Slope Formula: 
  
Explanation:
Step 1: Define
Point (17, -12)
Point (17, 8)
Step 2: Find slope m
Simply plug in the 2 coordinates into the slope formula to find slope m
- Substitute in points [Slope Formula]: 
  
- [Fraction - Denominator] Subtract: 
  
We cannot divide anything by 0.
∴ Our slope m is undefined and it would be a vertical line if graphed.