Question

Cho M = 3 + 3² +...+ 3²⁰¹⁶

Tính M ?

Answer 1

\(\)\(M=3+3^2+....+3^{2016}\)

=>\(3M=3.\left(3+3^2+...+3^{2016}\right)\)

=>\(3M=3^2+3^3+...+3^{2017}\)

=>\(3M-M=\left(3^2+3^3+....+3^{2017}\right)-\left(3+3^2...+3^{2016}\right)\)

=>\(2M=3^{2017}-3\)

=>\(M=\dfrac{3^{2017}-3}{2}\)

Chúc Bạn Học Tốt!!!

Answer 2

M = 3 + 3² +...+ 3²⁰¹⁶

3M = 3² + 3³ +...+ 3²⁰¹⁷

3M - M = (3² + 3³ +...+ 3²⁰¹⁷) - (3 + 3² +...+ 3²⁰¹⁶)

2M = 3²⁰¹⁷ - 3

M = \(\dfrac{3^{2017}-3}{2}\)

Answer 3

Ta có: M= 3+ 3²+.....+3²⁰¹⁶

3M= 3²+ 3³+......+ 3²⁰¹⁷

=> 3M-M=( 3²+ 3³+....+3²⁰¹⁷)-(3+ 3²+...+3²⁰¹⁶⁾

=> 2M= 3²⁰¹⁷- 3=> M=\(\dfrac{3^{2017}-3}{2}\)

Answer 4

\(M=3+3^2+...+3^{2016}\)

\(\Rightarrow3M=3\left(3+3^2+...+3^{2016}\right)\)

\(3M=3^2+3^3+...+3^{2017}\)

\(\Rightarrow3M-M=2M=\left(3^2+3^3+...+3^{2017}\right)-\left(3+3^2+...+2^{1016}\right)\)

\(2M=3^{2017}-3\Leftrightarrow M=\dfrac{3^{2017}-3}{2}\)

vậy \(M=\dfrac{3^{2017}-3}{2}\)

Answer 5

\(M=3+3^2+...+3^{2016}\)

\(3M=3^2+3^3+...+3^{2017}\)

\(3M-M=\left(3^2+3^3+...+3^{2017}\right)-\left(3+3^2+...+3^{2016}\right)\)

\(2M=3^{2017}-3\)

\(M=\dfrac{3^{2017}-3}{2}\)