Réponse :
ce sont des vecteurs
4) AB + KM + BA = KM
5) ED+DF+FE = EF + FE = 0
6) IJ + KI + JK = KI + IJ + JK = KJ + JK = 0
7) MN + PL - MN = PL
8) - EF - FE = FE - FE = 0
9) AB+MA+BN = MA+AB+BN = MB+BN = MN
10) AB+BA+BC-BC = 0
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2) (AB + CD) - (AB - DB) = AB + CD - AB + DB = CD+DB = CB
3) 1/2)AB + 3BD + 5/2)AB = 3AB + 3BD = 3(AB+BD) = 3AD
4) 5BA - 5BC = 5BA+5CB = 5CB+5BA = 5(CB+BA) = 5CA
5) 3AM - 2AN+MA = 3AM-2AN- MA = 2AM-2AN = 2AM+2NA = 2(NA+AM) = 2NM
6) (FG - EF) + (GF - KJ) - (EF -KJ) = FG-EF+GF-KJ-EF+KJ = FG-EF+GF-EF
= - 2EF
7) 1/3)RS + 7/3)SR = 1/3)RS-7/3RS = - 2RS
8) 2ST + 2/5)TS -ST = ST - 2/5)ST = 3/5)ST
Explications étape par étape
