Ta có : 264 chia a dư 24 \(\Rightarrow\) (264-24)\(⋮\) a \(\Rightarrow\)240 \(⋮\) a
636 chia a dư 43 \(\Rightarrow\)(636-43)\(⋮\) a \(\Rightarrow\)593 \(⋮\) a
\(\Rightarrow\) a \(\in\) ƯC(240;593)
Ta có : 240=\(^{2^4}\).3.5
593=593
\(\Rightarrow\)ƯCLN(240;593)=1
\(\Rightarrow\)ƯC(240;593)=Ư( 1 ) = {\(\pm\) 1}
Mà a>43 \(\Rightarrow\) a \(\in\)\(\varnothing\)