Bonjour,
A) 2+(-8)+7+(-12)+(-5)+4+(-2)
2-8+7-12 -5 +4 -2 = 2
B) -5+(-4)-15-(-6)+7
-5 -4 -15 +6 +7 = -11
C) -14-14+30+(-15)-(-20)
-14 -14 7 +30 -15 +20 = 7
D) -4+(-3)-5-3+(-2)
-4 -3 -5 -3 -2 = -17
E) 3-12+15-17-23= -34
règle :
-(-) =>+
+(+) => +
-(+) => -
+(-) => -