Bonjour,
A=2/3 - 5/13 : 10/16
A = 2/3 - 5/13 x 16/10
A = 2/3 - 5/10 x 16/13
A = 2/3 - 1/2 x 16/13
A = 2/3 - 16/2 x 1/13
A = 2/3 - 8 x 1/13
A = 26/39 - 24/39
A = 2/39
B =3-2/3 / 4/3 x7
B = (3 - 2/3) / (4/3 x 7)
B = (9/3 - 2/3) / (28/3)
B = 7/3 x 3/28
B = 7/28 x 3/3
B = 1/4