Answer:
y = 8
Explanation:
x = 4 is the equation of a vertical line parallel to the y- axis.
A perpendicular line will be a horizontal line with equation
y = c ( where c is the value of the y- coordinates the line passes through )
the line passes through (- 9, 8 ) with y- coordinate 8 , then
y = 8 ← equation of perpendicular line