Réponses

2014-04-23T22:58:42+02:00


25x²=(4x-5)²             25x²-(4x-5)²=[5x +(4x-5)][5x-(4x-5)]=(5x+4x-5)(5x-4x+5)=(9x-5)(x+5)

9x-5=0     9x=5   x=5/9

x+5=0    x=-5                      S={ 5/9; -5}

2x-2x+1/5 inf  6       0x+1/5 inf 6    impossible

x/3-4 sup 0     x/3sup 4     x sup 12