The line in the graph is decresent, so we expect its slope to be negative. To determine its value you need to use the following formula:
![m=(y_1-y_2)/(x_1-x_2)](https://img.qammunity.org/2023/formulas/mathematics/college/fimp7zvgzwrq4ecowqytytl3ydbrfr5mz1.png)
Where
m is the slope
(x₁,y₁) are the coordinates of one point of the line
(x₂,y₂) are the coordinates of a second point of the line
For the points (1,-3) and (2,-6), you can calculate the slope as:
![m=(-6-(-3))/(2-1)=(-6+3)/(1)=-3](https://img.qammunity.org/2023/formulas/mathematics/college/chyjfndp7rc5nb9e3dn3pfzi6burru4m83.png)
The slope of the line is m=-3