To find the slope of a line you need to know at least 2 points on that line to use their coordinates in the following formula:
[tex]m=\frac{y2-y1}{x2-x1}[/tex]That is the formula to find the slope of a line, m is the slope, y2 and y1 are the y coordinates of the known points and x2 and x1 are the x coordinates.
For example, find the slope of the line that passes through (1,4) and (3,12)
[tex]m=\frac{12-4}{3-1}=\frac{8}{2}=4[/tex]The slope of the line is 4.
