Réponse :
A = x + 1/x = x²/x + 1/x = (x²+1)/x x≠ 0
B = 3 + 4/(x + 1) = 3(x + 1)/(x+1) + 4/(x + 1) = (3(x+1) + 4)/(x + 1) = (3 x + 7)/(x+1)
x ≠ - 1
C = x - x²/(x+1) = x(x+1)/(x+1) - x²/(x+1) = (x²+ x - x²)/(x+1) = x/(x+1) x ≠ - 1
Explications étape par étape :