Ta có :
\(31^{11}< 32^{11}=16^{11}.2^{11}\)
\(16^{11}.2^{12}=16^{14}< 17^{14}\)
Lại có :
\(16^{11}.2^{11}< 16^{11}.2^{12}\)
\(\Rightarrow31^{11}< 16^{11}.2^{11}< 16^{11}.2^{12}< 17^{14}\)
\(\Rightarrow31^{11}< 17^{14}\)
Ta có:
\(31^{11}< 32^{11}\Leftrightarrow31^{11}< \left(2^5\right)^{11}\Leftrightarrow31^{11}< 2^{55}\left(1\right)\)
\(17^{14}>16^{14}\Leftrightarrow17^{14}>\left(2^4\right)^{14}\Leftrightarrow17^{14}>2^{56}\left(2\right)\)
Từ (1) và (2) ta có:
\(31^{11}< 17^{14}\)