Bonjour,
F = 1/2-3/4×16/9
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=1/5-3/10×1/6+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 = 42/60 - 3/60
G = 39/60
G = 3 x 13 / 3 x 20
G = 13/20
H=(1/5-3/10)×(1/6+1/2)
H = (1 x 2 / 5 x 2 - 3/10) * (1/6 + 1 x 3 / 2 x 3)
H = (2/10 - 3/10) * (1/6 + 3/6)
H = - 1/10 * 4/6
H = - 4/60
H = 4 x - 1 / 4 x 15
H = - 1/15