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 = 1/2 - (6 x 8) / (6 x 6)
F = 1/2 - 8/6
F = (1 x 3) / (2 x 3) - 8/6
F = 3/6 - 8/6
F = - 2/6
F = (2 x - 1) / (2 x 3)
F = - 1/3
G = 1/5 - 3/10 x 1/6 + 1/2
G = 1/5 - 3/60 + 1/2
G = (1 x 4) / (5 x 4) - (3 x 1) / (3 x 20) + (1 x 10) / (2 x 10)
G = 4/20 - 3/20 + 10/20
G = 11/20
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.