Question

Tìm nϵN biết 5 ≤ 5⁴ ≤ 625  

Answer 1

\(5\le5^n\le625\) 

\(\Rightarrow5^1\le5^n\le5^4\)

\(\Rightarrow1\le n\le4\)

Mà: \(n\in N^+\)

\(\Rightarrow n=\left\{1;2;3;4\right\}\)

Answer 2

Sửa đề:

5 ≤ 5ⁿ ≤ 625

5 ≤ 5ⁿ ≤ 5⁴

1 ≤ n ≤ 4

n ∈ {1; 2; 3; 4}