Respuesta :

The slope of the line that contains the points (1 -1) and (-2 8) is -3

Step-by-step explanation:

Slope measures the steepness of a line. It is the ratio of vertical change to horizontal change. If the line increasing, the slope is positive and if the line is decreasing the slope is negative. If the line is horizontal slope is zero and if the line is vertical slope is undefined.

Equation for slope = (y2-y1)/(x2-x1)

here y2= 8

x2=-2

y1=-1

x1=1

Substituting the following,

slope = (8+1)/(-2-1)

=9/-3

=-3

hence the slope is -3