回復 7# shihtc 的帖子
填充第1題
\(\begin{align}
& x=\frac{4y-3}{5} \\
& y>0,y\equiv 2\ or\ 7\ \left( \bmod \ 10 \right) \\
& y<0,-y\equiv 3\ or\ 8\ \left( \bmod \ 10 \right) \\
\end{align}\)
利用\({{60}^{2}}+{{80}^{2}}={{100}^{2}}\)
\(\left( x,y \right)=\left( -59,-73 \right),\left( -55,-68 \right),\cdots ,\left( 57,72 \right),\left( 61,77 \right)\)
