Réponse :
Bjr,
A = -1.8 - (2-7.8) +3.9
A = -1.8 - 2 +7.8 +3.9
A = -3.8 + 11.7
A = 7.9
B = -0.5 * (-2-8) - 1.7
B = -0.5*-10 -1.7
B = 5 - 1.7
B = 3.3
C = 4.7 - (1-10.5)*4
C = 4.7 - (-9.5)*4
C = 4.7 - (-38)
C = 4.7 + 38
C = 42.7
J'espère avoir pu vous aider