bonjour
d = ( 2 x - 5) ( 3 x +7)
d = 6 x² + 14 x - 15 x - 35
d = 6 x² - x - 35
E = ( 4 x + 3)²
E = 16 x² + 24 x + 9
on ne voit pas la totalité du schéma
F = 3 - 7/5 - 17/20
F = 60/20 - 28/20 - 17/20 = 15/20 = 3/4
G = 2/3 + 7/4 - 1/5
G = 8/12 + 21/12 - 1/5
G = 40/60 + 105/60 - 12/60
G = 133/60
H = 3/4 - ( - 5/12 - 1/3) + ( - 2 - 1/6)
H = 3/4 - ( - 5/12 - 4/12) + ( - 12/6 - 1/6)
H = 3/4 - ( - 9/12) - 13/6
H = 9/12 + 9/12 - 26/12
H = - 26/12 = - 13/6