Find the equation of a line

Question

Find the equation of the line vertically through (-3,0)

Answer 1

Vertical lines mean that no matter what y value you choose, the x value is the same. Thus, our answer should only have x in it because the line does not depend on y. The x coordinate of the point (-3,0) is -3, so that is the one value that x always takes, no matter what y is. 

 

Then the equation is given by x=-3

 

In general, vertical lines are always x equals some constant, and horizontal lines are always y equals some constant