Persamaan garis yg melalui titik A(1,5) dan B(4,11) adalah

(y-y1)/(y2-y1) = (x-x1)/(x2-x1)
(y-5)/(11-5) = (x-1)/(4-1)
(y-5)/6 = (x-1)/3
3y-15 = 6x-6
3y-6x = 15-6
3y-6x = 9
y-2x = 3

X-x1. x2-x1
____ = ______
y-y1. y2-y1

×-1. 4-1
___ = ____
y-5. 11-5

×-1. 3
___ = __
y-5. 6

6x-6 = 3y-5
6x-3y = -5+6
6x-3y = 1
semoga bener…