Question

1/2 + 1/4+1/8+1/16+1/32+1/64

Answer 1

mọi người giúp minh giải câu hỏi này đi ạ

 

Answer 2

1/2+1/4+1/8+1/16+1/32+1/64
= 2 x (1/2+1/4+1/8+1/16+1/32+1/64)
            = 1 + 1/2+1/4+1/8+1/16+1/32
=> 2A - A = (1+1/2+1/4+1/8+1/16+1/32) - (1/2+1/4+1/8+1/16+1/32+1/64)
=> A = 1 - 1/64
         = 63/64

Answer 3

\(1-\dfrac{1}{2}=\dfrac{1}{2}\)

\(\dfrac{1}{2}-\dfrac{1}{4}=\dfrac{1}{4}\)

Vậy A = \(1-\dfrac{1}{2}+\dfrac{1}{2}-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{8}+\dfrac{1}{8}-\dfrac{1}{16}+\dfrac{1}{16}-\dfrac{1}{32}+\dfrac{1}{32}-\dfrac{1}{64}\)

=\(1-\dfrac{1}{64}=\dfrac{63}{64}\)