Answer:
x = 7
Step-by-step explanation:
y = 4 is a horizontal line that passes through the point (0, 4).
A line perpendicular to y = 4 is a vertical line.
In a vertical line, all points have the same x-coordinate.
Since the point (7, 2) is on the vertical line we want, and its x-coordinate is 7, then x-coordinate of all the points on the line we want is 7.
Answer: x = 7
