Explanation:
Find slope between the two points
slope = m = (y1-y2)/(x1-x2) = (1-2)/(-3-3) = -1/-6 = 1/6
then point (3,2) slope form is
y - 2 = 1/6 ( x -3) expand
y - 2 = 1/6 x - 1/2 multiply everything by '6' to get rid of the fraction
6y - 12 = x - 3 re-arrange to
x - 6y = -9 Done.