$x^3 + x^2 + 1$ and $x^3 + x + 1$ are both irreducible over $\mathbb{F}_2[x]$, so then we have isomorphism of fields:
$$ \mathbb{F}_2[x]/(x^3 + x^2 + 1) \simeq \mathbb{F}_2[t]/(t^3 + t + 1) \simeq \mathbb{F}_8 $$
Then do we have that $x \mapsto t$ is an isomorphism?