\(216\le6^n< 1296\)
\(6^3\le6^n< 6^4\)
\(\Rightarrow n=3\)
\(216=6^3;1296=6^4\)
\(\Rightarrow6^3\le6^n< 6^4\)
\(n=3\)
Ta có: \(216\le6^n< 1296\)
\(\Leftrightarrow6^3\le6^n< 6^4\)
\(\Leftrightarrow3\le n< 4\)
Vì \(n\inℕ\)\(\Rightarrow n=3\)
Vậy \(n=3\)