Réponse:
c'est très simple regarde :
exercice 7 :
(2x-7) (x+1) = 0
2x-7 = 0 x+1 = 0
2x = 7 x = -1
x = 7/2
S = { 7/2 ; -1 }
(6x-8) (7x+2) = 0
6x-8 = 0 7x+2= 0
6x = 8 7x = -2
x = 8/6 x = -2/7
S = { 8/6 ; -2/7 }
(x+2) (3x-5) = 0
x+2 = 0 3x-5 = 0
x = -2 3x = 5
x = 5/3
S = { -2 ; 5/3 }
