Question 460308
The graph of x = 7 is a vertical line IN THE CARTESIAN PLANE because the points contained in such line are of the form (7, y).  Since the x-value is fixed while the y-values are free to change, the locus is a line that has a constant distance of 7 units from the y-axis, hence is parallel to the latter.  Since the y-axis is vertical by definition, the graph of x = 7 must also be a vertical line.

BTW, {{{y = (-3/4)x + 2}}} is easier to graph, ONLY BECAUSE plugging in values for x gives the y-values right away, whereas in the top equation, you still have to go through a bit of arithmetic to get y.  BUT the the two equations have the SAME graph.