Réponses

2013-05-20T18:13:43+02:00

b) 2/3 + 4/30 :          2/3 = 20/30             20/30 + 4/30 = 24/30 = 8/10

 

c) 17/18 - 1/6            1/6 = 3/18                      17/18 - 3/18 = 14/18 = 7/9

 

d) 1/21 + 2/3              2/3 = 7/21                 1/21 + 7/21 = 8/21