4х - (3х - (2х - (х - 1) - 2) - 3) - 4 = 0
4x - (3x - (2x - x + 1 - 2) - 3) - 4 = 0
4x - (3x - x + 1 - 3) - 4 = 0
4x - (2x - 2) - 4 = 0
2x = 2
x = 1
4*1 - (3*1 - (2*1 - (1 - 1) - 2) - 3) - 4 = 0
4 - (3 - (2 - 0 - 2) - 3) - 4 = 0
4 - (3 - (2 - 2) - 3) - 4 = 0
4 - (3 - 0 - 3) - 4 = 0
4 - 0 - 4 = 0
0 = 0
Ответ: {1}