Assuming x is real.......
Note that 4 l x - 1l can be written as 4sqrt [ (x -1)^2 ]
So we have that
(x -1)^2 - 4sqrt [ (x - 1)^2 ] + 3 = 0
(x - 1)^2 + 3 = 4sqrt [ (x - 1)^2 ] square both sides
(x - 1)^4 + 6 (x-1)^2 + 9 = 16 (x - 1)^2
(x - 1)^4 - 10(x - 1)^2 + 9 = 0
Let (x -1)^2 = a.......so we have
a^2 - 10a + 9 = 0 factor
(a - 9) ( a - 1) = 0
Set each factor to 0 and solve for a
So
a = 9 or a = 1
So
(x -1)^2 = 9 or ( x -1)^2 = 1 take both roots
x - 1 = 3 x - 1 = -3 x -1 = 1 x -1 = -1
x = 4 x = -2 x = 2 x = 0