Question

so sánh giùm mik bài này cái

3²¹ và 2³¹

Answer 1

\(3^{21}=3^{20}.3=9^{10}.3\)

\(2^{31}=2^{30}.2=8^{10}.2\)

Do \(9^{10}>8^{10},3>2\)

\(\Rightarrow9^{10}.3>8^{10}.2\Rightarrow3^{21}>2^{31}\)

Answer 2

\(3^{21}=3^{20}\cdot3\)

\(2^{31}=2^{30}\cdot2\)

mà \(3^{20}>2^{30}\)

nên \(3^{21}>2^{31}\)