Réponses

2014-01-08T14:42:03+01:00

A= 3/20 + 2/15= 3x3/20x3 + 2x4/15x4 = 9/60 + 8/60 = 17/60

B= -3/8 - 7/6 = -3x3/8x3 - 4x7/6x4 = -9/24 - 28/24 = -37/24

C= 3/7 + -2/5 = 5x3/7x5 - 2x7/7x5 = 15/35 - 14/35 = 1/35

D= 1/2 - 3/4 + 5/6 = 1x6/2x6 - 3x3/4x3 + 5x2/6x2 = 6/12 - 9/12 + 10/12 = 7/12

J'espère qu'il y a assez de détails ^^