Answer:
Step-by-step explanation:
The slope of a line between two points can be calculated by dividing the difference of y values by the difference of x values
in this case
[tex]m = \frac{y_2-y_1}{x_2-x_1} = \frac{15-(-10)}{-15-6} = \frac{25}{-21} = \frac{-25}{21}[/tex]