Question

Find an equation for the line that passes through the point (2, −9) and is parallel to the y-axis.

Answer 1

If the line is parallel to y-axis, then x is a constant for that line. x for the given point equals 2, so all other points of the line will have x=2.

An equation for the line that passes through the point (2, −9) and is parallel to the y-axis is  x=2.