Réponse:
exercice1 :
a) 9x^2 = 100
= √100 ÷ √9
x = 10/3
b) (2x + 3)^2 - 121 = 0
(2x + 3)^2 - 11^2= 0
((2x + 3) - 11) ((2x + 3) + 11) = 0
d'où: 2x + 3 - 11 = 0 ou 2x + 3 + 11 = 0
2x = 8 ou 2x = 14
x = 8/2 ou x = 14/2
x = 4 ou x= 7
c) 3x - 5 / x+1 = 0
3x - 5 = x+1
3x - x = 5 + 1
2x = 6
x = 6/2
x = 3
d) x/4 + x - 1 = 1/3 (2 - x/2 )
(3x + 12x - 12) / 12 = 2/3 - x/6
(3x + 12x - 12) / 12 = (8 - 2x) / 12
3x + 12x + 2x = 8 + 12
17x = 20
x = 20 / 17
