Réponses

2014-09-22T07:50:51+02:00
-2/7 X (1/3 + 1/6 -1/9)
-2/7 X (6/18 +3/18 -2/18)
-2/7 X ( 7/18)
-14/126 = -7/63 = -1/9
2014-09-22T07:57:10+02:00
- 2/7 x (1/3 + 1/6 - 1/9)
= - 2/7 x (1 x 6 / 3 x 6 + 1 x 3 / 6 x 3 - 1 x 2 / 9 x 2
= - 2/7 x (6/18 + 3/18 - 2/18)
= - 2/7 x 7/18
= - 14/126
= 14 x - 1 / 14 x 9
= - 1/9