Question

So sánh 199^20 và 2017^15

Answer 1

Ta có:

199²⁰ = (199⁴)⁵ < (200⁴)⁵

2017¹⁵ = (2017³)⁵ > (2000³)⁵

Mà 199⁴ < 200⁴ < 2000³ < 2017³ 

=> 199²⁰ < 2017¹⁵  

Answer 2

Ta có: \(199^{20}< 200^{20}\)

            \(2017^{15}>2000^{15}\)

Lại có: \(200^{20}=\left(200^4\right)^5=\left(16.10^8\right)^5\)

           \(2000^{15}=\left(2000^3\right)^5=\left(8.10^9\right)^5=\left(80.10^8\right)^5\)

Do \(16.10^8< 80.10^8\)

\(\Rightarrow200^{20}< 2000^{15}\)

\(\Rightarrow199^{20}< 2017^{15}\)