Answer: Undefined, or 0
Step-by-step explanation:
We will use the formula for slope. Let (-8, 6) be point 1 and (-8, 2) be point 2.
[tex]\displaystyle \frac{y_{2} -y_{1} }{x_{2} -x_{1} }[/tex]
[tex]\displaystyle \frac{2-6 }{-8--8}[/tex]
[tex]\displaystyle \frac{2-6 }{-8+8}[/tex]
[tex]\displaystyle \frac{-4 }{0}[/tex]
You cannot divide by 0. This means the line is straight up/down, or vertical, and has an undefined slope.