tentukan persamaan garis melalui titik (-2,1)dan (-4,17)

(x1,y1)= (-2, 1)
(x2,y2) = (-4 , 17)

y - y1 = (y2-y1)/(x2 -x1) (x - x1)
y - 1=  (17-1)(-4 +2  (x  + 2)
y - 1 = (16/-2)  (x + 2)
y - 1 = -8( x+2)
y = - 8x - 16 + 1
y = -8x - 15
atau
8x +y + 15 = 0

(-2,1) => x1 = -2 , y1 = 1
(-4,17) => x2 = -4 , y2 = 17

mencari persamaan garis
y - y1 / y2 - y1 = x - x1 / x2 - x1
y - 1 / 17 - 1 = x - (-2) / -4 - (-2)
y -1 / 16 = x + 2 / -2
(diperkecil)
y - 1 / 8 = x + 2 / -1
-1(y - 1) = 8(x + 2)
-y + 1 = 8x + 16
-y = 8x + 16 - 1
-y = 8x + 15
8x + y + 15 = 0

semoga membantu