|x + 3| - |x| = x
|x + 3| - |x| - x = 0
→ Separam ecuatia in 4 cazuri posibile
x + 3 - x - x = 0 => x + 3 ≥ 0, x ≥ 0
-(x + 3) - x - x = 0 => x + 3 < 0, x ≥ 0
x + 3 - (-x) - x = 0 => x + 3 ≥ 0, x < 0
-(x + 3) - (-x) - x = 0 => x + 3 < 0, x < 0
→ Rezolvam in continuare
x = 3, x ≥ -3, x ≥ 0
x = -1, x < -3, x ≥ 0
x = -3, x ≥ -3, x < 0
x = -3, x < -3, x < 0
→ Gasim intersectia solutiilor pt1
x = 3, x ∈ [0, +∞)
x = -1, x ∈ ∅
x = -3, x ∈ [-3, 0)
x = -3, x ∈ (-∞, -3)
→ Gasim intersectia solutiilor pt2
x = 3
x ∈ ∅
x = -3
x ∈ ∅
→ Reunim solutiile
x = -3
x = 3
=> x₁ = -3 iar x₂ = 3
