101. 求解 $x^2\equiv 322(\mod 999)$.
Posted by haifeng on 2015-12-18 17:21:16 last update 2016-01-07 23:48:16 | Answers (0) | 收藏
求解 $x^2\equiv 322(\mod 999)$.
证明: 仅有这些数是解
\[
\begin{aligned}
(999k+454)^2\equiv 322\ (\mod 999),\\
(999k+491)^2\equiv 322\ (\mod 999),\\
(999k+508)^2\equiv 322\ (\mod 999),\\
(999k+545)^2\equiv 322\ (\mod 999).\\
\end{aligned}
\]
类似的, 求解 $x^2\equiv 223(\mod 999)$.
证明: 仅有这些数是解
\[
\begin{aligned}
(999k+149)^2\equiv 223\ (\mod 999),\\
(999k+445)^2\equiv 223\ (\mod 999),\\
(999k+554)^2\equiv 223\ (\mod 999),\\
(999k+850)^2\equiv 223\ (\mod 999).\\
\end{aligned}
\]