( -1 2/5 + (- 3,6)) + ( - 2 5/6 + ( - 2/3))
1) -1 2/5 + (- 3,6) = - 7/5 + (- 3 6/10) = - 7/5 + (- 3 3/5) = - 7/5 + (- 18/5) = - 7+18/5 = - 25/5 = -5
2) - 2 5/6 + ( - 2/3) = - 17/6 + ( - 4/6) = - 17+4/6 = - 21/6 = - 7/2
3) - 5 + (- 7/2) = - 4 2/2 + (- 7/2) = - 10/2 + ( - 7/2) = - 3/2 = - 1 1/2