\(x^{50}+x^{10}+1=x^{20}\left(x^{30}-1\right)+\left(x^{20}+x^{10}+1\right)\)
\(=x^{20}\left(x^{10}-1\right)\left(x^{20}+x^{10}+1\right)+\left(x^{20}+x^{10}+1\right)\)
\(=\left(x^{20}+x^{10}+1\right)\left(x^{30}-x^{20}+1\right)⋮\left(x^{20}+x^{10}+1\right)\forall x\)