Douglas B. answered 03/24/21
Algebra tutor with masters degree in applied math
There are no steps for this type of problem: you need only recognize that for a vertical line, the x-value is constant. So, the answer to your question is x = 6.
If instead we were asked to find the horizontal line through (6,4), the answer would be y = 4 (because for a horizontal line, the y-value is constant).
For a line in the plane that is not vertical or horizontal, we need to use either the point-slope or y-intercept formula to find the equation. This will involve some algebraic steps.