\(a+b+c=0\)
\(\Rightarrow\left(a+b+c\right)^2=0\)
\(\Rightarrow a^2+b^2+c^2+2\left(ab+bc+ca\right)=0\)
\(\Rightarrow a^2+b^2+c^2=0\) vì \(ab+bc+ca=0\)
\(\Rightarrow\left\{{}\begin{matrix}a=0\\b=0\\c=0\end{matrix}\right.\)
\(\Rightarrow A=\left(0-1\right)^{2023}+0^{2024}+\left(0+1\right)^{2025}=-1+0+1=0\)