Question

so sánh hai lũy thừa 

27¹³....243⁸ ;  125⁸⁰....25¹¹⁸

Answer 1

\(27^{13}=\left(3^3\right)^{13}=3^{39};243^8=\left(3^5\right)^8=3^{40};3^{39}< 3^{40}\Rightarrow27^{13}< 243^8\\ 125^{80}=\left(5^3\right)^{80}=5^{240};25^{118}=\left(5^2\right)^{118}=5^{236};5^{240}>5^{236}\Rightarrow125^{80}>25^{118}\)

Answer 2

\(27^{13}< 243^8;125^{80}>25^{118}\)

Answer 3

\(125^{80}=\left(5^3\right)^{80}=5^{240}\\ 25^{118}=\left(5^2\right)^{118}=5^{236}\)

Vì \(5^{240}>5^{236}\)nên \(125^{80}>25^{118}\)