4/(x+1) - 1/(x-1)= (3x-5)/(x²-1)
4/(x+1) - 1/(x-1) - (3x-5)/(x²-1) = 0
4(x-1)/(x+1)(x-1) - (x+1)/(x+1)(x-1) - (3x-5)/(x+1)(x-1) = 0
[4(x-1) - (x+1) - (3x-5)]/(x+1)(x-1) = 0
[4x-4 - x-1 - 3x+5]/(x+1)(x-1) = 0
[3x-5 - 3x+5]/(x+1)(x-1) = 0
[3x - 5 - 3x + 5]/(x+1)(x-1) = 0
0 = 0
c'est démontré.
En espérant t'avoir aidé
