Making graphical representations allow you to plot points and compute for the equation of the line following available derived formula to compute linear formula given two points.
The principal equation is the point-slope formula y=mx+b
Where, m = slope or rate of how the elevation or depression between two reference points.
Say for example you have pt 1 (1,1) and pt 2(0,0)
compute first for slope where m = (y2-y1)/(x2-x1) = (0-1)/(0-1) = 1
Now using point slope formula given p1 (1,1) and slope of m=1
(y-y1)=m(x-x1)
y-1=(1)(x-1)
y=x
