bonsoir
dans l'ordre
1 x ( - 3 ) = - 3
( - 1 ) x ( - 5 ) = 5
( - 3 ) x ( - 1 ) = 3
( - 1 ) x 3 = - 3
( - 5 ) x ( - 1 ) = 5
1 x ( - 5 ) = - 5
