Réponses

2013-11-23T22:17:12+01:00
A) -2/1.3 + 2/3.9 = -6/3.9 +2/3.9=-4/3.9
b) 7/11 -12/9=63/99 - 121/99=-58/99
c)21/27 -14/18 =21/27- 21/27=0