Exercice n'11: Calcule:
A = 19+ (8-25);
B=(-15+6)-(23-18)
C = (154-6) +3-(-9+7):
D=-13+ (5+8)-(-4+8)
E = (-5)-(17+ (-13))-((-8) - (+2)):
F = (12-(-3)) - (12-(-3))
G=15-(-3-((+12)-16)):
H=-12-(-15 +30) -(65-20) - 20