Je te détaille le calcul en deux expressions pour que tu comprennes car pas évident de faire la fraction complète sur téléphone :
A = x / y
x = 3/2 - 1/3
x = 9/6 - 2/6
x = 7/6
y = 3/4 + 2/3
y = 9/12 + 8/12
y = 17/12
A = 7/6 / 17/12
A = 7/6 x 12/17
A = 12/6 x 7/17
A = 2 x 7/17
A = 14/17
B = 2 + 2/7 / 5/14
B = 2 + 2/7 x 14/5
B = 2 + 14/7 x 2/5
B = 2 + 2 x 2/5
B = 2 + 4/5
B = 10/5 + 4/5
B = 14/5
C = - 3/14 - 3/(7/5) + 2
C = - 3/14 - 3 x 5/7 + 2
C = - 3/14 - 15/7 + 2
C = - 3/14 - 30/14 + 28/14
C = - 33/14 + 28/14
C = - 5/14
D = 7/5 + (8/15) / (2/3) - 19/2
D = 7/5 + 8/15 x 3/2 - 19/2
D = 7/5 + 8/2 x 3/15 - 19/2
D = 7/5 + 4 x 1/5 - 19/2
D = 7/5 + 4/5 - 19/2
D = 11/5 - 19/2
D = 22/10 - 95/10
D = - 73/10