Answer
The slope is $4$.
Work Step by Step
The plot of the given points is shown below. It also shows that all the points lie in a single line.
To find the slope of the line passing through the given points, pick any two of the given points and then use the formula for finding the slope of the line passing through two points.
The formula for finding the slope, $m$, of the line passing through two points, $(x_1,y_1)$ and $(x_2,y_2)$ is given by $m=\frac{y_1-y_2}{x_1-x_2}$. With $(x_1,y_1)=(2,-18)$ and $(x_2,y_2)=(5,-6)$, then
$$\begin{aligned}
m&=\frac{y_1-y_2}{x_1-x_2}
\\&=
\frac{-18-(-6)}{2-5}
\\&=
\frac{-18+6}{2-5}
\\&=
\frac{-12}{-3}
\\&=
4
.\end{aligned}
$$
Hence, the slope of the line, $m$, passing through the given points is $4$.