Functions and quadratic

If 2 roots of (c-1)(x²+x+1)²-(c+1)(x⁴+x²+1)=0 are real and distinct and f(x)=1-x1+x then
f{f(x)}+f{f(1x)}=
a]-c
b]c
c]2c
d]none of these

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∑ ∑ ∑ ∑ ∑ ∮ ∮ ∮ ∮ ∮ ∏ ∏ ∏ ∏ ∏ ∐ ∐ ∐ ∐ ∐

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° ∂ ∞ α β γ δ θ λ μ ν ξ π ρ σ φ ω ε ƒ κ τ υ Γ Δ Λ Σ Π Ω