Question

1/3+1/12+1/48+1/192+..........................+1/3072

 

Answer 1

giúp mình với nhé các bạn

Answer 2

phân số à

Answer 3

\(A=\frac{1}{3}+\frac{1}{12}+....+\frac{1}{3072}\)

\(A\times4=\frac{4}{3}+\frac{1}{3}+...+\frac{1}{3072:4}\)

Lấy \(A\times4-A\)ta có:

\(A\times4-A=A\times3=\frac{4}{3}+\frac{1}{3}+...+\frac{1}{768}-\left(\frac{1}{3}+\frac{1}{12}+...+\frac{1}{3072}\right)\)

\(A\times3=\frac{4}{3}+\frac{1}{3}+...+\frac{1}{768}-\frac{1}{3}-\frac{1}{12}-...-\frac{1}{3072}\)

\(A\times3=\frac{4}{3}-\frac{1}{3072}\)

\(A\times3=\frac{1365}{1024}\)

\(A=\frac{1365}{1024}:3=\frac{455}{1024}\)