First, find the slope:
slope = (y2 - y1) / (x2 - x1)
slope = (3 - -6) / (6 - -5)
slope = (3 + 6) / (6 + 5)
slope = 9 / 11
Now we do point-slope form:
y - y1 = m(x - x1)
y - 3 = (9/11)(x - 6)
y - 3 = (9/11)x - 54/11
Now we move things around and try to get it to standard form
(-9/11)x + y - 3 + 54/11 = 0
(-9/11)x + y - 33/11 + 54/11 = 0
(-9/11)x + y + 11/11 = 0
(-9/11)x + y + 1 = 0
-9x + 11y + 11 = 0
9x - 11y - 11 = 0
(that's standard form)