(3 1/3 - 1 5/6): 2 1/6 - 1 1/3 * 2,4=
(3 1/3 - 1 5/6) / 2 1/6 - 1 1/3 * 2,4 = (3 2/6 / 1 5/6) / 2 1/6 - 4 /3 * 24/10 = 1 3/6 / 2 1/6 - 16/5 = 9/6 / 15/6 - 16/5 = 3/5 - 16/5 = - 13/5 = - 2,6