Réponse :
Bonjour
Explications étape par étape
A = (-8 + 12 -5 +7) X (11 -13 -7 -2)
A = (-13 + 19) X ( -11)
A = +6 X -11
A = -66
B = -7 X 3 -9 X (-5) + (-4) X 9 -7
B = -21 +45 -36 -7
B = -19
C = 6 - ( -4 X (-3) +5 X (-2)) X -4
C = 6 - ( 12 -10) X -4
C = 6 - (2 X -4)
C = 6 -2 X 4
C = 6 -8 = -2