The slope is calculated as,
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]
So from the graph, let us condier two points, that lies on the line.
(1,2) and (2,4) are two points.
So the slope is,
[tex]m=\frac{4-2}{2-1}=1[/tex]
This will be true for all the points lying on the line.
