Réponse :
Bonjour,
Explications étape par étape :
5x - 3 = 7x + 8
5x - 3 - 7x = 7x + 8 - 7x
-2x - 3 = 8
-2x - 3 + 3 = 8 + 3
-2x = 11
-2x/-2 = 11/-2
x = -5,5
4x + 8 = 7x + 7
4x + 8 - 7x = 7x + 7 - 7x
-3x + 8 = 7
-3x = -1
-3x/-3 = -1/-3
x = 1/3
-2x + 8 = 3x + 18
-2x + 8 - 3x = 3x + 18 - 3x
-5x + 8 = 18
-5x = 10
-5x/-5 = 10/-5
x = -2
6x + 12 = -4x - 18
6x + 12 + 4x = -4x - 18 + 4x
10x + 12 = - 18
10x = -30
10x/10 = -30/10
x = -3
Voilà :)
