Réponses

2013-11-25T19:25:30+01:00
A= 4/3 - (4/7 - 11/7) 
=4/3-(-7/7)
=4/3+1
=4/3+3/3
=7/3

B= 7/11 - (-4/11 + 2/3) 
=7/11+4/11-2/3
=11/11-2/3
=1-2/3
=3/3-1/3
=2/3