bonsoir
17 + 23 = 40
- 4 + 6 = 2
- 1 + ( - 3 ) = - 1 - 3 = - 4
3 + ( - 4 ) = 3 - 4 = - 1
3 + ( - 2 ) = 3 - 2 = 1
- 4 + ( - 3 ) = - 4 - 3 = - 7
