Answer:
y = - 10
Explanation:
A line perpendicular to the y- axis is a horizontal line parallel to the x- axis.
The equation of a horizontal line is
y = c
where c is the value of the y- coordinates the line passes through.
The line passes through (4, - 10) with y- coordinate of - 10, thus
y = - 10 ← is the equation of the line