Question

So sánh 

a) \(3^{86}và2^{129}\)

b)\(5^{217}và119^{72}\)

Answer 1

a) \(3^{86}=\left(3^2\right)^{43}=9^{43}\)

\(2^{129}=\left(2^3\right)^{43}=8^{43}\)

\(\Rightarrow9^{43}>8^{43}\)

\(\Rightarrow3^{86}>2^{129}\)

b) Ta có :

\(5^{127}>5^{126}=\left(5^3\right)^{72}=125^{72}>119^{72}\)

 \(\Rightarrow5^{127}>5^{126}\text{Hoặc}125^{72}>119^{72}\)

\(\Rightarrow5^{127}>119^{72}\)

Answer 2

làm câu b rõ hơn được ko bạn

kk

kk

Answer 3

a)

  Ta có:

          \(3^{86}=\left(3^2\right)^{43}=9^{43}>8^{43}=\left(2^3\right)^{43}=2^{129}\)

b)

         \(119^{72}< 125^{72}=5^{216}< 5^{217}\)