Bonjour
Commence par calculer :
1/2 +1/4 +1/3 +1/6
= (1 x 30) / (2 x 30) + (1 x 15) / (4 x 15) + (1 x 20) / (3 x 20) + (1 x 10) / (6 x 10)
= 30/60 + 15/60 + 20/60 + 10/60
= 75/60
87/60 - 75/60 = 12/60 = (12 x 1) / (12 x 5) = 1/5
Donc :
87/60 = 1/2 + 1/4 + 1/3 + 1/6 + 1/5.
