Réponses

2014-01-02T14:45:47+01:00
Meilleure réponse !
2014-01-02T14:54:22+01:00
B = 8/5 : 21/10
B =  8/5 x 10/21
B = 80/105
B = 80 : 5 / 105 : 5
B = 16/21

C = 5/7 + 9/2 x 1/14
C = (5 x 2 / 7 x 2 + 9 x 7 / 2 x 7) x 1/14
C = (10/14 x 63/14) x 1/14
C = 630/14 x 1/14
C = 630/196
C = 45/14

D = 5 - 7 x (-2)
             5²
D = -2 x -2
           5²
D = 4/25