The first step is to find out two axes ('x' or horizontal and 'y' or vertical axes) in Coordinate Plane to graph Mathematical Expression. Horizontal line is the x-axis, on which x- coordinates are graphed, and vertical line is y-axis, with y- coordinates. Point where two axes i.e. 'x' and y- axis is called as origin (It is a fixed Point for reference).
In coordinate system each and every point is represented by two Numbers written in parentheses separated by a comma: (X, Y). Where, 'X' represents the coordinate graphed on x- axis and y represents the coordinate graphed on y- axis. Way to plot coordinates is just to count the number of units on x or y- axes according to the measure specified. These measures are taken from a reference point that is known as origin and is represented as (0, 0). For example, to graph a point (7, 12), count seven units to right of origin, then move 12 units up and mark the point.
Sometimes you may find a need to solve for two coordinates by using general algebraic operations. For instance, given formula y = 2x + 4, pick the values for 'x', say, 0, 1, -2 and 3, and put them in formula to get 4, 6, 0 and 10 respectively, giving you coordinates (0, 4), (1, 6), (-2, 0), (3, 10). Graph these points and draw a line connecting them to get the desired expression.