If a=-9 and b=-6, show that (a-b) unequal (b-a) a - b: a - b = -9 - -6 a - b = -9 + 6 a - b = -3 b - a: b - a = -6 - -9 b - a = -6 + 9 b - a = 3 Since -3 <> 3, then a - b <> b - a