Answer
point-slope form: $y+4=0$ (since slope is $0$).
Refer to the image below for the graph.
Work Step by Step
(A)
To graph the line with the given point and slope (slope is $\dfrac{\text{rise}}{\text{run}}$), perform the following steps:
(1) Plot the point P(2, -4).
(2) A slope of $0$ means the line is horizontal. Plot any point with the same y-coordinate as $P$.
(3) Connect the two points using a straight line to complete the graph.
(refer to the attached image below)
(B)
The point-slope form of a line's equation is $y-y_1 = m(x-x_1)$ where $m$= slope and $(x_1, y_1)$ is a point on the line.
With $m=0$ and $P(2, -4)$ on the line, the point-slope form of the equation of the line is:
$y-(-4)=0(x-2)
\\y+4=0$