Tentukan gradien suatu garis yang melalui A (-2,-8) dan B (1,1) P(2,3) dan Q (-1,0)

A(-2, -8) dan B(1, 1)
x1 = -2
x2 = 1
y1 = -8
y2 = 1

m = (y2 - y1)  / (x2 - x1)
    = (1 - (-8)) / (1 - (-2))
    = 9 / 3
    = 3

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P (2, 3) dan Q (-1, 0)
x1 = 2
x2 = -1
y1 = 3
y2 = 0

m = (y2 - y1)  / (x2 - x1)
    = (0 - 3) / (-1 - 2)
    = -3 / -3
    = 1