line through A and S.
what is the slope?
m = (y2 - y1) / (x2 - x1)
m = (2 - 4) / (9 - -1)
m = -2 / 10
m = -1/5
perpendicular to that is slope = 5
now we want slope = 5, passing through the point (-3, 3)
point-slope form
y - y1 = m (x - x1)
y - 3 = 5 (x - -3)
y - 3 = 5 (x + 3)
y - 3 = 5x + 15
y = 5x + 18