Final answer:
The graph of the equation x=-4 is a vertical line that crosses the x-axis at -4 and has an undefined slope.
Step-by-step explanation:
The equation x=-4 represents a vertical line on a Cartesian coordinate system. When we graph this equation, we simply draw a straight line that crosses the x-axis at the point x=-4 and extends infinitely in both directions along the y-axis. This line is vertical because it does not change in the x-direction, meaning no matter what y-value you have, the x-coordinate will always be -4. This type of line has an undefined slope because it does not run horizontally at all, so we cannot measure a rise over run, as the run would be zero.