Bonjour,
A = 11/3 - 8/3 : (- 16/5)
A = 11/3 - 8/3 x - 5/16
A = 11/3 + 40/48
A = 11 x 48 / 3 x 48 + 40 x 3 / 48 x 3
A = 528/144 + 120/144
A = 648/144
A = 72 x 9 / 72 x 2
A = 9/2
B = 1 - 3/2 + 9/7
5/4 - 1/3
B = 1 x 14 / 1 x 14 - 3 x 7 / 2 x 7 + 9 x 2 / 7 x 2
5 x 3 / 4 x 3 - 1 x 4 / 3 x 4
B = 14/14 - 21/14 + 18/14
15/12 - 4/12
B = 11/14 : 11/12
B = 11/14 x 12/11
B = 132/154
B = 22 x 6 / 22 x 7
B = 6/7