Question

Tìm số tự nhiên n biết :

2.2^2_.2³......2ⁿ=1024

Answer 1

2.2².2³....2ⁿ = 1024

2.2².2³....2ⁿ = 2¹⁰

=> 1+2+3+...+n = 10

(n+1).n : 2 = 10

(n+1).n = 10.2

(n+1).n = 20

(n+1).n = 5.4

=> n = 4

Answer 2

Ta có: \(2.2^2.2^3.....2^n=1024\)

\(\Rightarrow2.2^2.2^3......2^n=2^{10}\)

\(\Rightarrow1+2+3+...+n=10\)

\(\Rightarrow n=4\)