The line \(x = -1\) is a vertical line which passes through -1 ... The shape has been reflected in the line \(y = 1\). The equation of a straight line graph has the form \(y = mx + c\), where ...

and \({x} = {c}\), will either be a horizontal or vertical line. All the points on the horizontal line below have a y-coordinate of \(4\), so you can say that the equation of the line is \(y = 4\).