If $x_1,x_2,\dots,x_n \in \mathbb{R}$ can we claim that:
$x_1^3+x_2^3+\dots+x_n^3+x_1+x_2+\dots+x_n=0$
implies
$x_1+x_2+\dots+x_n=0$ ?
If $x_1,x_2,\dots,x_n \in \mathbb{R}$ can we claim that:
$x_1^3+x_2^3+\dots+x_n^3+x_1+x_2+\dots+x_n=0$
implies
$x_1+x_2+\dots+x_n=0$ ?
No, we cannot. Here is a counterexample: $n=6$, $x_1=x_2=x_3=x_4=x_5=1$ and $x_6=-2$.