Answer:
x=5
Explanation;
y=4 is a horizontal line, and we know this because all we have is the y intercept; 4 (the y-intercept is the point on the line that intercepts the y axis) There is also no x value. This is the equation for a horizontal line:
y=b
B is the y-intercept.
A line perpendicular to a horizontal line would be a vertical line. This is the equation for a vertical line:
x=d
D is the x-intercept (the point on the line that intercepts the x axis)
So to answer the question, we just need to plug the x value of the point (5,2) into x=d.
(5,2)-> 5 is the x coordinate
Therefore, x=5
I hope this helps! Please comment if you have any questions.