Question

What is the equation of a vertical line passing through (1, 7)?

Answer 1

A vertical line's slope is undefined, and
So it's x=1

Answer 2

Vertical lines have equations of the form: x = a constant. In your ordered pair, what does x equal?

Answer 3

Vertical line => x coordinate is the same
So, it is in the form x= a, where a is a constant.
Since it passes through (1,7), what would it be?