Slope

Given two points $(x_{1},y_{1})$ and $(x_{2},y_{2})$ , the slope between these two points is $m={\frac {y_{2}-y_{1}}{x_{2}-x_{1}}}$ . That is, the slope between two points is the difference between the y-coordinates of the points, divided by the difference between the x-coordinates of the points. For example, the slope between the two points (1, 3) and (5, 6) is ${\frac {6-3}{5-1}}={\frac {3}{4}}$ . The slope between (-1, -1) and (15, -21) is ${\frac {-21-(-1)}{15-(-1)}}={\frac {-21+1}{15+1}}={\frac {-20}{16}}={\frac {-5}{4}}$ .