Modul de x+2x+1+modul de 1-x,dacă x maimic decât 0


Răspuns :

|x+2x+1|+|1-x| , x<0

|3x+1| + |1-x| < 0

3x + 1 + 1 - x < 0

2x + 2 < 0 /-2

2x < -2 /:2

x < -1

x ∈ (-∞ ; -1)