Réponse:
EXERCISE 1
1) +5-8=-3.
2) -9-8=-17.
3) -4+7-5=-2.
EXERCISE 2
1) -18+15=-3
2) +11-15=-4
3) 20-32=-12
EXERCISE 3
1a)-1338,-1327
b) -1327
2)-2528,-2483,-2473,-1338,-1327,-1213
EXERCISE 4
-a
+b
-c
