Réponse :
b) On obtient -13 car (7*(-3)+4) - (5*(-3)+11) = -13
c) Réponse A.
d)
1.
(7x + 4)-(5x + 11) = 0
7x + 4 = 5x + 11
7x + 4 -4 = 5x +11 -4 (LIGNE FACULTATIVE)
7x = 5x + 7
7x -5x = 5x + 7 -5x (LIGNE FACULTATIVE)
2x = 7
x = 3.5
2.
7x + 4 - 5x - 11 = -19
2x - 7 = -19
2x - 7 +7 = -19 +7
2x = -12
x= -6
