Réponse :
Bonjour ,
Explications étape par étape
1) 2x+1= -4
2x = -4-1= -5
x = -5/2
2) 12-6x =3/2
-6x = 3/2 - 12 = 3/2 -24/2 = -21/2
x = -21/12
3) 2x -5 = x - (3x +4)
= x -3x - 4
= -2x -4
2x+ 2x = +5-4 =1
x = 1/4
4) 3/5x +1/5 = 2/5x -1/5
3/5x-2/5x =-1/5 -1/5 = -2/5
1/5x = -2/5
-10 x = 5
x = - 5/10 = -1/2
