Expand $(\sqrt{t} + 2t)^4+(\sqrt{t} - 2t)^4$.

$t^2+8t\left(\sqrt{t}\right)^3+24t^3+32t^3\sqrt{t}+16t^4+\left(\sqrt{t}-2t\right)^4$

$t^2+8t\left(\sqrt{t}\right)^3+24t^3+32t^3\sqrt{t}+16t^4+t^2-8t\left(\sqrt{t}\right)^3+24t^3-32t^3\sqrt{t}+16t^4$

$32t^4+48t^3+2t^2$

-Vinculum