Réponse :
Explications étape par étape
Bonjour
A) 3x+5=2x+4
3x - 2x + 5 = 2x + 4 - 2x
x + 5 - 5 = 4 - 5
x = -1
B) 5-2=7x-6
3 = 7x - 6
3 + 6 = 7x - 6 + 6
9 = 7x
7x/7 = 9/7
x = 9/7
C) 3(2x+4)=5-x
6x + 12 = 5 - x
6x + x = 5 - 12
7x = -7
7x/7 = -7/7
x = -1