Réponses

2014-09-04T13:09:40+02:00
-2/3 + 5/7 = - 2 x 7 / 3 x 7 + 5 x 3 / 7 x 3 = 14/21 + 15/21 = 29/21

1 + 8/11 = 1 x 11 / 1 x 11 + 8/11 = 11/11 + 8/11 = 19/11

27/2 × 5/4 = 135/8

1/3 ÷ 13/4 = 1/3 x 4/13 = 4/39