Line symbols are used to represent the events that are localized on lines (for example, lines of watershed, lines of tectonic breaks) and the demarcating lines (borders of regions, states) and in order to mark objects that have linear character, that are not manifested by its width in a scale such as rivers, roads, ...
What is the symbol of linear equation?
The general form of a linear equation is expressed as Ax + By + C = 0, where A, B, and C are any real numbers and x and y are the variables