Question

How do you write an equation of the line in standard form with vertical line through (21,-37)?

Answer 1

`color(green)(x=21)`

Explanation:

For a vertical line, the value of `x` is a constant.

If you insist on the explicit standard form: `Ax+By=C`
then you could write this as:
`color(white)("XXX")1x+0y=21`