Answer
$slope=-\frac{5}{2}$
Work Step by Step
To calculate the slope between points $(x_1,y_1)$ and $(x_2,y_2)$, we use the formula:
$slope=m=\frac{y_2-y_1}{x_2-x_1}$
We see that the two blue points on the line are: $(-3,3)$ and $(-1,\ -2)$. We plug in the points into the slope equation:
$slope=m=\frac{y_2-y_1}{x_2-x_1}=\frac{-2-3}{-1-(-3)}=\frac{-5}{2}=-\frac{5}{2}$