To find the equation of a vertical line through the point (-4,-12), we need to know that a vertical line has the equation of the form x = a, where 'a' is the x-coordinate of any point on the line.
In this case, the x-coordinate is -4 since the line passes through the point (-4,-12). Therefore, the equation of the line in standard form is x = -4.
Standard form of a linear equation is given by Ax + By = C, where A, B, and C are constants. In this case, since the line is vertical, there is no y-variable involved, so B = 0. The equation can be rewritten as x + 0y = -4, which simplifies to x = -4.