exercice 1svp rien compris mrc d'avance

                                                                                                     - 2160

                                                                                               -24          90 

                                                                                             4           -6        -15

                                                                                   2           2           -3         +5

                  54 

       -3                 -18

      -1        +3       -   6

1       - 1      -3      + 2