persamaan garis yang melalui titik (-3,6) dan (1,4)

..........................

Y-y1 x-x1
------- = ------
Y2-y1 x2-x1

Y- 6 x- (-3)
------- = ---------
4 - 6 1 - (-3)

Y- 6 x + 3
------- = ------
-2 4

4y - 24 = -2x - 6
2x + 4y - 18 =0