Réponses

2014-09-17T15:57:32+02:00
= ( 1 - 1 / 3 - 1 / 4 ) x 2 / 5
= ( 12 / 12 - 4 / 12 - 3 / 12 ) x 2 / 5
= ( 8 / 12  - 3 / 12 ) x 2 / 5
= 5 / 12 x 2 / 5
= 10 / 60
= 1 / 6