x = 1 - x + x^2 - x^3 + x^4 rearrange as
1 - 2x + x^2 - x^3 + x^4 = 0
1 is a root.......using synthetic division to find the remaining polynomial
1 [ 1 -1 1 -2 1 ]
1 0 1 - 1
_________________________
1 0 1 - 1 0
The remaining polynomial is
x^3 + x - 1
Set to 0
x^3 + x - 1 = 0 no easy algebraic way to solve this
WolframAlpha shows the other real root as x ≈ .68233