Réponses

2014-02-10T14:08:16+01:00
1-(1/4+3/3x4/5)=
1 - (1/4 + (3/3 x 4/5)) =
3/3 = 1
1 x 4/5 = 4/5
(1/4 + 4/5) = (5/20 + 16/20) = 21/20
1 - 21/20 = 20/20 - 21/20 = -1/20
est-ce assez clair
je me suis tromper sur l'opération 1-(1/4+3/4x4/5)
Bonjour j'ai remodifié l'opération
merci beaucoup
2014-02-10T14:14:40+01:00
1-(1/4+3/4x4/5)= 1 - (1/4 + 3x4 / 4x5)
                        = 1 - ( 1/4 + 3/5 )
                       = 1 - ( 1x5 / 4x5 + 4x3 /4x5 )
                       = 1 - ( 5/20 + 12/20)
                       = 1 - ( 17/20)
                      =  1x20 /20 -17/20
                      = 20/20 -17/20
                       = 3/20