1 2 0 0 1 2 and 2 4 are all on the same line by computing th

(-1, 2), (0, 0), (1, -2) and (2, -4) are all on the same line by computing the slope between each pair of points What is the slope between (-1, 2) and (0, 0)?

Solution

the poins given are:
(x1,y1) = (-1,2)
(x2,y2) = (0,0)

slope is given by:
slope = (y2-y1)/(x2-x1)
     = (0-2)/(0 - (-1))
      = (-2)/1
      = -2

Answer: - 2