Question

Các tìm kiếm liên quan đến Cho A = 1 + 3 + 3² + 3³ + ... + 3²⁰⁰⁰. Biết 2A = 3ⁿ - 1. Khi đó n =

 

Answer 1

n = không biết  :))))

Answer 2

Ta có:

         \(A=1+3+3^2+.........+3^{2000}\)

\(\Rightarrow3.A=3+3^2+3^3+...........+3^{2001}\)

Khi đó: \(3.A-A=\left(3+3^2+3^3+......+3^{2001}\right)-\left(1+3+3^2+......+3^{2000}\right)\)

\(\Rightarrow2.A=3^{2001}-1\)

\(\Rightarrow n=2001\)

Vậy: n = 2001.

Answer 3

\(3A=3+3^2+...+3^{2001}\)

\(\Rightarrow3A-A=\left(3+3^2+...+3^{2001}\right)-\left(1+3+...+3^{2000}\right)\)

\(\Rightarrow2A=3^{2001}-1\)

\(\Rightarrow3^{2001}-1=3^n-1\)

\(\Rightarrow3^{2001}=3^n\)

\(\Rightarrow n=2001\)

Vậy n = 2001

Answer 4

ⁿ⁼²⁰⁰¹