Question Number 200885 by cortano12 last updated on 26/Nov/23
$$\:\:\:\:\cancel{\underline{\underbrace{\boldsymbol{{x}}}}} \\ $$
Commented by cortano12 last updated on 26/Nov/23
$$\:\:\:\boldsymbol{\mathfrak{f}} \\ $$
Answered by Frix last updated on 26/Nov/23
$${a}^{\mathrm{4}} +{b}^{\mathrm{4}} +\left({a}+{b}\right)^{\mathrm{4}} =\mathrm{2}\left({a}^{\mathrm{2}} +{ab}+{b}^{\mathrm{2}} \right)^{\mathrm{2}} \\ $$