Bonjour
A = 2/3 : 4
A = 2/3 x 1/4
A = 2/12
A = (2 x 1) / (2 x 6)
A = 1/6
B = 2 : 3/4
B = 2 x 4/3
B = 8/3
C = (1/2 - 1/4) : 1/4
C = [(1 x 2) / (2 x 2) - 1/4] : 1/4
C = (2/4 - 1/4) : 1/4
C = 1/4 : 1/4
C = 1/4 x 4
C = 4/4
C = 1
D = (2/3 - 1) : (2/3 + 1)
D = [2/3 - (1 x 3) / (1 x 3)] : [2/3 + (1 x 3) / (1 x 3)]
D = (2/3 - 3/3) : (2/3 + 3/3)
D = - 1/3 : 5/3
D = - 1/3 x 3/5
D = - 3/15
D = (3 x - 1) / (3 x 5)
D = - 1/5.
