(1, 12)
(420, 12)
Any coordinate with a y value of 12 lies on the line y = 12.
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(-5, 69)
(-5, 13)
Any coordinate with an x value of -5 lies on the line x = -5.
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Since the equation must be perpendicular to the line x = 4, which is a vertical line, it must also be written in the form x = a.
Since the x coordinate is 3, the equation of the line is simply x = 3.