- The document discusses graphing linear equations where a = 1 and b = 0, which produces a vertical line. - It shows that the equation 1x + 0y = c is equivalent to x = c, and the graph of x = c is a vertical line passing through the point (c, 0). - It concludes that for any equation of the form ax + by = c, where a = 1 and b = 0, the graph will be a vertical line.