Réponses

Meilleure réponse !
2013-03-12T17:47:39+01:00

a= (3/5-1/4)/(1+2/5)

= (3x4/5x4 - 1x5/4x5) / (1x5/1x5 + 2/5)

= 12-5 / 20

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5+2 / 5

 

= 7/20

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7/5

 

= 7/20 x 5/7

= 1/4 x 1/1

= 1/4