Bonjour
1)
A = 1 - (2/3 + 1/4)
A= (1 x 12) / (1 x 12) - [(2 x 4) / (3 x 4) + (1 x 3) / (4 x 3)]
A = 12/12 - (8/12 + 3/12)
A = 12/12 - 11/12
A = 1/12
B = (3 - 5/2) : (1 + 1/5)
B = [(3 x 2) / (1 x 2) - 5/2] : [(1 x 5) / (1 x 5) + 1/5]
B = (6/2 - 5/2) : (5/5 + 1/5)
B = 1/2 : 6/5
B = 1/2 x 5/6
B = 5/12
2)
C = 4/5 x 35/8
C = 140/40
C = (20 x 7) / (20 x 2)
C = 7/2
3)
A + B + C
= 1/12 + 5/12 + 7/2
= 1/12 + 5/12 + (7 x 6) / (2 x 6)
= 1/12 + 5/12 + 42/12
= 48/12
= 4.
