Réponse :
Bonsoir
Explications étape par étape
4x +7 = 19
4x = -7 +19
4x = +12
x = 12/4
x = 3
Vérification
4x +7 = 19
4 X 3 + 7 = 19
12 +7 = 19
19 = 19
-5x +6 =-4
-5x = -6 -4
-5x -10
x = 10/5
x = 2
Vérification
-5x +6 = -4
-5 X 2 = -6 -4
-10 = -10
7x -5 = 16
7x = +5 +16
7x = +21
x = 21/7
x = 3
Vérification
7x -5 = 16
7 X 3 -5 = 16
21 -5 = 16
16 = 16