Answer:
x = 2
Explanation:
y = 4 is a horizontal line parallel to the x- axis.
A line perpendicular to it will be vertical and parallel to the y- axis with equation
x = c ( where c is the value of the x- coordinates the line passes through )
The line passes through (2, - 7 ) with x- coordinate 2 , then
x = 2 ← equation of perpendicular line