Bonsoir pouvez vous m’aider svp (14point)

Bonsoir
A = 2/5 + 3/5 x 15/9
A = 2/5+ 45/45
A = 2/5 + 1
A = 2/5 + (1 x 5) / (1 x 5)
A = 2/5 + 5/5
A = 7/5
B = 8/3 x (3/2 - 1/4)
B = 8/3 x [(3 x 2) / (2 x 2) - 1/4]
B = 8/3 x (6/4 - 1/4)
B = 8/3 x 5/4
B = 40/12
B = (4 x 10) / (4 x 3)
B = 10/3
C = (8/5 + 9/10) x (3/4 - 7/20)
C = [(8 x 2) / (5 x 2) + 9/10] x [(3 x 5) / (4 x 5) - 7/20]
C = (16/10 + 9/10) x (15/20 - 7/20)
C = 25/10 x 8/20
C = 200/200
C = 1