the graph of f passes through (3,9) and is perpendicular to the line whose equation is x=18

Question

I need to find out how to get the equation of the perpendicular line

Answer 1

the line whose equation is x=18 is a vertical line parallel to the y-axis and going through the point (18,0)

the line that is perpendicular to this line and going through the point (3,9) is the line that is parallel to the x-axis and goes through the y-axis at the point (0,9)

the equation of the line is y=9

Answer 2

 Y = 9

 

X = 18  is parallel to Vertical ( Y- axis), and Y= 9 is parallel with horizontal axis.