Answer:
The answer to your question is  m = -5/3 
Explanation:
Data
Point 1 = (1, -6)
Point 2 = (-8, 9)
Process
To find the slope just substitute the values in the formula and simplify.
Formula
slope = m = (y2 - y1) / (x2 - x1)
-Identify x1, y1, x2 and y2
 x1 = 1 y1 = -6 x2 = -8 y2 = 9
-Substitution
 m = (9 + 6) / (-8 - 1)
-Simplification
 m = 15/-9
-Result
  m = -5/3