Bonjour,
D = ( -2 ) - ( -5 )
D = ( -2 ) + 5
D = 3
E = ( +2 ) - ( +5 )
E = + 3
F = ( -2 ) - ( -1 ) - ( +4 )
F = -2 + 1 - 4
F = - 2 - 4 + 1
F = - 6 + 1
F = - 5
G = ( + 10 ) - ( + 15 )
G = - 5
H = ( -2 ) + ( - 5 ) - ( - 1 )
H = - 2 - 5 + 1
H = - 7 + 1
H = - 6
I = ( - 8 ) + ( + 1 ) - ( - 8 ) - ( + 1 ) - ( + 2 )
I = - 8 - 1 - 2 + 1 + 8
I = - 11 + 9
I = - 2
