Réponse :
A = x/3 - 7 x/3 = - 6 x/3 = - 2 x/1
B = 2 x - (2 x - 5)/4 = (8 x - 2 x + 5)/4 = (6 x + 5)/4
C = (3 x + 2)/3 - (6 x - 2)/6 = (2(3 x + 2) - 6 x + 2)/6 = (6 x + 4 - 6 x + 2) = 6/6 = 1/1
D = 2 x/(x + 1) - x/(x - 1) il faut que x ≠ - 1 et x ≠ 1
= (2 x(x-1) -x (x + 1))/(x-1)(x+1)
= (2 x² - 2 x - x² - x)/(x-1)(x+1)
= (x² - 3 x)/(x-1)(x+1)
Explications étape par étape :