Réponses

2013-09-22T13:06:20+02:00
2/3-1/3=1/3 donc 1/3x(1+1/2)
1/3x(2/2+1/2)=1/3x3/2=3/6=1/2
2013-09-22T13:23:19+02:00
2/3 -1/3 X (1+1/2)
1/3 X (2/2 +1/2)
1/3 X 3/2 
3/6 = 1/2

Voilà