Réponses

2014-09-03T16:36:48+02:00
A = 3*(2-7)
A = 3*(-5) 
A = -15

A = 3*(2-7)
A = 3*2+3*(-7)
A = 6-21
A = -15

B = (3-5)*(5+2)
B = (-2)*(7)
B = -14

B = (3-5)*(5+2) 
B = 3*5+3*2-5*5-5*2
B = 15+6-25-10
B = -14

C = 4*(2,5)+4*(7,5)
C = 10+30
C = 40

C = 4*(2,5)+4*(7,5)       - Tu remarques l'existence d'un facteur commun : 4
C = 4*(2,5+7,5)
C = 4*10
C = 40