4,6 : (1 2/3 - 3,2) + 1 3/8

1) 1 2/3 - 3,2 = 5/3 - 16/5 = 25/15 - 48/15 = - 23/15 2) 4,6:(-23/15) = 46/10 * (-15/23) = -3 3) -3 + 1 3/8 = -2 8/8 + 1 3/8 = -1 5/8 = -1,625