Question

Rút gọn 
A= 1+1/2+1/22+1/2³+...+1/2²⁰¹⁵

Answer 1

A = \(1+\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}+...+\frac{1}{2^{2015}}\)

2A = \(2+1+\frac{1}{2}+\frac{1}{2^2}+...+\frac{1}{2^{2014}}\)

2A - A =\(2+1+\frac{1}{2}+\frac{1}{2^2}+...+\frac{1}{2^{2014}}\)\(-\left(1+\frac{1}{2}+\frac{1}{2^2}+...+\frac{1}{2^{2015}}\right)\)

A = \(2-\frac{1}{2^{2015}}\)

 

 

Answer 2

Katherine Lilly Filbert trả lời đúng rồi đấy