The formula for determining slope is expressed as
Slope = (y2 - y1)/(x2 - x1)
y2 and y1 are the final and initial coordinates of y
x2 and x1 are the final and initial coordinates of x
From the information given,
x1 = 1, y1 = - 7
x2 = - 7, y2 = - 10
Slope = (- 10 - - 7)/(- 7 - 1)
Slope = (- 10 + 7)/- 8
Slope = - 3/- 8
Slope = 3/8