Answer:
x = 0
Explanation:
The equation of a line is shown by using the formula y = mx+b
But, in special cases like this one, where the line is completely vertical then we use the same formula but we just adjust it.
When a line is completely straight up and down the equation is x = #
Since the line is on the y-axis (or has a x value of zero) the equation is x = 0.
There is no y in this equation because the line is hitting all values of y (which means y is ∞) with only 1 value of x. (As opposed to most equations where one or multiple values of y with one value of x or vise-versa.)