Réponse :
Bonjour
(2x - 3)(7x + 6) = -18
⇔ 14x² + 12x - 21x - 18 = -18
⇔ 14x² - 9x - 18 = -18
⇔ 14x² - 9x = 0
⇔ x(14x - 9) = 0
⇔ x = 0 ou 14x - 9 = 0
⇔ x = 0 ou 14x = 9
⇔ x = 0 ou x = 9/14
S = {0 ; 9/14}