Ta có: 2189 = (23)63 = 863
3126 = (32)63 = 963
Vì 8 < 9 => 863 < 963 => 2189 < 3126
\(2^{189}=\left(2^9\right)^{21}=512^{21}\)
\(3^{126}=\left(3^6\right)^{21}=729^{21}\)
Vì \(512^{21}< 729^{21}\Rightarrow2^{189}< 3^{126}\)
Vậy \(2^{189}< 3^{126}\)