Final answer:
The equation of a line perpendicular to y = 9 and passing through the point (-7, -1) is x = -7, which represents a vertical line.
Step-by-step explanation:
The question asks us to find the equation of a line that is perpendicular to the line described by y = 9. The provided equation, y = 9, has a slope of zero because it is a horizontal line. To find a perpendicular line, we need a line with an undefined slope, which means a vertical line.
Given that we have a point (− 7, − 1), the vertical line passing through this point will have an equation of x = − 7, which does not depend on y because the x-coordinate is constant for all points on the vertical line.