What kind of straight line will be the graph of x = -4? 

Concept Used:

The equation x = a represents a vertical line i.e., parallel to y-axis; in a Cartesian coordinate system. In this equation, "a" is a constant, and it signifies that all the points on the line have the same x-coordinate, which is equal to "a."

Explaination:

The equation x = -4 represents a vertical straight line that is parallel to the y-axis. 

This line intersects the y-axis at the point (-4, 0) and continues infinitely both upward and downward along the y-axis.