slope (1,-19) (-2,-7)
The formula for slope: m = (y2 - y1) / (x2 - x1)
For this problem (x1, y1) = (1, -19) ---> x1 = 1, y1 = -19
(x2, y2) = (-2, -7) ---> x2 = -2, y2 = -7
Placing these numbers into the formula: m = (-7 - -19) / (-2 - 1) ---> m = 12 / -3 ---> m = -4