Réponses

2014-01-22T19:59:19+01:00
2014-01-22T19:59:38+01:00
A) 12/21 = 4 x 3 / 7 x 3 = 4/7

b) 20/28 = 4 x 5 / 4 x 7 = 5/7

12/21 < 20/28