Point slope form is written as:
y - y_1 = m * (x - x_1), where y_1 and x_1 are the y and x coordinates of the given point and m is the slope.
The slope, we know, is -6, and the given point is (-2, -4). Plug these into the equation:
y + 4 = -6 * (x + 2)
And, that's your answer!