Question

So sánh: 

\(5^{21}\)và \(4\times5^{20}\)

Answer 1

\(5^{21}=5^{20}.5\)

Mà \(5^{20}.5>5^{20}.4\)nên \(5^{21}>4.5^{20}\)

Answer 2

\(5^{21}< 4\times5^{20}\)

Answer 3

5^21=5^20 x5 > 5^20 x 4

Answer 4

\(4\times5^{20}< 5\times5^{20}=5^{20+1}=5^{21}\)