(y - 3) / (-3 - 3) = (x - 1) / (-2 - 1)
(y - 3) / (-6) = (x - 1) / (-3)
-3 * (y - 3) = -6 * (x - 1)
-3y + 9 = -6x + 6
6x - 3y + 3 = 0
2x - y + 1 = 0
Ответ: 2x - y + 1 = 0