persamaan garis lurus yang melalui titik (3,1) dan (-5,5)

Persamaan garis dari 2 titik
(3 , 1)
( -5 , 5)

(y - y1) / (y2 - y1) = (x - x1) / (x2 - x1)
(y - 1) / ( 5 - 1) = ( x - 3)/ ( -5-3)
(y-1)/4 = (x-3) / -8

4(x - 3) = -8(y - 1)
----------------------- ÷ 4
x - 3 = -2(y - 1)
x - 3 = -2y + 2
x - 3 + 2y - 2 = 0
x + 2y - 5 = 0

y-y1/y2 - y1 = x -x1/x2-x1
y-1/5-1 = x-3/-5-3
y-1/4 = x-3/-8
-8(y-1) = 4(x-3)
-8y + 8 = 4x -12
-8y = 4x -12 -8
-8y = 4x -20
4x + 8y -20 = 0
x + 2y - 5 = 0