Bonjour,

E = (1/2 - 3/4) x 16/9

E = [(1 x 2) / (2 x 2) - 3/4] x 16/9

E = (2/4 - 3/4) x 16/9

E = - 1/4 x 16/9

E = - 16/36

E = (4 x - 4) / (4 x 9)

E = - 4/9

F = 1/2 - 3/4 x 16/9

F = 1/2 - 48/36

F = (1 x 18) / (2 x 18) - 48/36

F = 18/36 - 48/36

F = - 30/36

F = (6 x - 5) / (6 x 6)

F = - 5/6

G = 1/5 - 3/10 x 1/6 + 1/2

G = 1/5 - 3/60 + 1/2

G = (1 x 12) / (5 x 12) - 3/60 + (1 x 30) / (2 x 30)

G = 12/60 - 3/60 + 30/60

G = 39/60

G = (3 x 13) / (3 x 20)

G = 13/20.

H = (1/5 - 3/10) x (1/6 + 1/2)

H = [(1 x 2) / (5 x 2) - 3/10] x [1/6 + (1 x 3) / (2 x 3)]

H = (2/10 - 3/10) x (1/6 + 3/6)

H = - 1/10 x 4/6

H = - 4/60

H = (4 x - 1) / (4 x 15)

H = - 1/15.