Answer
$$m = 0$$
Because the slope is zero, the line is horizontal.
Work Step by Step
To find the slope, we use the formula:
$$m = \frac{y_{2} - y_{1}}{x_{2} - x_{1}}$$
We now plug in the given points into this equation to find the slope of this line:
$$m = \frac{4 - 4}{6 - (-3)}$$
Simplify:
$$m = \frac{0}{9}$$
$$m = 0$$
Because the slope is zero, the line is horizontal.