Réponses

2014-01-03T11:57:51+01:00
A = 1/2 + 2/3 + 3/4 + 4/5 + 5/6 
A = 15/30 + 20/30 + 24/30 + 25/30 + 3/4
A = 35/30 + 24/30 + 25/30 + 3/4
A = 59/30 + 25/30 + 3/4
A = 84/30 + 3/4
A = 3360/120 + 90/120
A = 3450/120
A = 345/12
A = 115/4

B = 1/2 + 1/3 + 1/4 + 1/5 + 1/6
B = 15/30 + 10/30 + 6/30 + 5/30 + 1/4
B = 25/30 + 11/30 + 1/4
B = 36/30 + 1/4
B = 6/5 + 1/4
B = 24/20 + 5/20
B = 29/20

C = 1/2 - (1/3 + 1/4) - (1/5 + 1/6).

C = 1/2 - (4/12 + 3/12) - (6/30 + 5/30)
C = 1/2 - (7/12) - (11/30)
C = 30/60 - (35/60) - (22/60)
C = -5/60 - 22/60
C = -27/60
C = -9/20
2014-01-03T11:58:31+01:00