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