Bonjour
S'il y a des erreurs d'énoncé tu ne t'en prendras qu'à toi même, la moindre des choses c'est que tu les recopies, pj inzoomable et petits caractères
A = - 7/5 x 1/2 - 3/10 x 3/4
A = - 7/10 - 9/40
A = (- 7 x 3) / (10 x 3) - 9/40
A = - 21/40 - 9/40
A = - 30/40
A = (10 x - 3) / (10 x 4)
A = - 3/4
B = (3/2 - 5/4) x 2/3 - (7/6 - 1)
B = [(3 x 2) / (2 x 2) - 5/4] x 2/3 - [7/6 - (1 x 6) / (1 x 6)]
B = (6/4 - 5/4) x 2/3 - (7/6 - 66)
B = 1/4 x 2/3 - 1/6
B = 2/12 - 1/6
B = (2 x 1) / (2 x 6) - 1/6
B = 1/6 - 1/6
B = 0
C = (9/4 - 1/2) : 3/2 + 1/3 (7/2 - 2)
C = [9/4 - (1 x 2) / (2 x 2)] : 3/2 + 1/3 [7/2 - (2 x 2) / (1 x 2)]
C = (9/4 - 2/4) : 3/2 + 1/3 (7/2 - 4/2)
C = 7/4 : 3/2 + 1/3 x 3/2
C = 7/4 x 2/3 + 3/6
C = 14/12 + 3/6
C = (2 x 7) / (2 x 6) + 3/6
C = 7/6 + 3/6
C = 10/6
C = (2 x 5) / (2 x 3)
C = 5/3.