Slope of the line through $$$\left(-1, 4\right)$$$ and $$$\left(14, -2\right)$$$

The slope of a line passing through two points $$$P = \left(x_{1}, y_{1}\right)$$$ and $$$Q = \left(x_{2}, y_{2}\right)$$$ is given by $$$m = \frac{y_{2} - y_{1}}{x_{2} - x_{1}}$$$.

We have that $$$x_{1} = -1$$$, $$$y_{1} = 4$$$, $$$x_{2} = 14$$$, and $$$y_{2} = -2$$$.

Plug the given values into the formula for a slope: $$$m = \frac{-2 - 4}{14 - \left(-1\right)} = - \frac{2}{5}$$$.

The slope of the line is $$$m = - \frac{2}{5} = -0.4$$$A.