pouvez vous m'aider svp?

A = 1 - (3 - 2/5)  + (1/2 + 7/5)
A = 1 x 10 / 1 x 10 - (3 x 10 / 1 x 10 - 2 x 2 / 5 x 2) + (1 x 5 / 2 x 5 + 7 x 2 / 5 x 2)
A = 10/10 - (30/10 - 4/10) + (5/10 + 14/10)
A = 10/10 - 26/10 + 19/10
A = 55/10
A = 5 x 11 / 5 x 2
A = 11/2