1+2+4+8+.........+256+512=1023

k mk nha

làm bạn nha

Tự nghĩ nha con

Nhớ tk đó

^_^

đáp số là 1023 nha bạn

1/2 + 1/4+ 1/8+ 1/16 + 1/32 + 1/64 + 1/128 + 1/256 + 1/512
= 1 – 1/2 + 1/2- 1/4 + 1/4 – 1/8 + 1/8 – 1/16 + 1/16 – 1/32 + 1/32 – 1/64 + 1/64 – 1/128 + 1/128 – 1/256 – 1/256 – 1/512
= 1 – 1/512

= 511/512 .

1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 + 1/256 + 1/512 + 1/1024 

Ta có : 
1/512 = 1×2 / 512×2 = 2/1024 

1/256 = 1×4 / 256×4 = 4/1024 

1/128 = 1×8 / 128×8 = 8/1024 

1/64 = 1×16 / 64×16 = 16/1024 

1/32 = 1×32 / 32×32 = 32/1024 

1/16 = 1×64 / 16×64 = 64/1024 

1/8 = 1×128 / 8×128 = 128/1024 

1/4 = 1×256 / 4×256 = 256/1024 

1/2 = 1×512 / 2×512 = 512/1024 
___________________________ 

=> 
1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64 + 1/128 + 1/256 + 1/512 + 1/1024 

= 512/1024 + 256/1024 + 128/1024 + 64/1024 + 32/1024 + 16/1024 + 8/1024 + 4/1024 + 2/1024 + 1/1024 

= (512 + 256 + 128 + 64 + 32 + 16 + 8 + 4 + 2 + 1) / 1024 

= 1023/1024 

255/256

\(A=1+\dfrac{1}{2}+1+\dfrac{1}{4}+1+\dfrac{1}{8}+...+1+\dfrac{1}{256}+1+\dfrac{1}{512}=\)

\(=1x\left(\dfrac{512-2}{2}+1\right)+\left(\dfrac{1}{2}+\dfrac{1}{4}+\dfrac{1}{8}+\dfrac{...1}{256}+\dfrac{1}{512}\right)=\)

\(256+B\)

\(2B=1+\dfrac{1}{2}+\dfrac{1}{4}+...+\dfrac{1}{512}+\dfrac{1}{1024}\)

\(B=2B-B=1+\dfrac{1}{1024}\)

\(\Rightarrow A=265+1+\dfrac{1}{1024}\)

1 + 1 = 2

2 + 2 = 4

4 + 4 = 8

8 + 8 = 16

16 + 16 = 32

32 + 32 = 64

64 + 64 = 128

128 + 128 = 256 

256 + 256 = 512

512 + 512 = 1024 

1024 + 1024 = 2048

Các kết quả bạn ghi đều nối kết quả với nhau nên mình không cần tính , chỉ cần tính ở đoạn 1024 cộng 1024 thôi !

1+1=2

2+2=4

4+4=8

8+8=16

16+16=32

32+32=64

64+64=128

128+128=256

256+256=512

512+512=1024

1024+1024=2048

1 + 1 = 2                                             2 + 2 = 4

4 + 4 = 8                                             8 + 8 = 16

16 + 16 = 32                                        32 + 32 = 64

64 + 64 = 128                                      128 + 128 = 256

256 + 256 = 512                                   512 + 512 = 1024 

1024 + 1024 = 2048

bạn tk mik nha

Đặt \(A=\dfrac{1}{2}+\dfrac{1}{4}+\dfrac{1}{8}+...+\dfrac{1}{256}+\dfrac{1}{512}\)

\(\Rightarrow2A=1+\dfrac{1}{2}+\dfrac{1}{4}+...+\dfrac{1}{128}+\dfrac{1}{256}\)

\(\Rightarrow A=2A-A=1+\dfrac{1}{2}+\dfrac{1}{4}+...+\dfrac{1}{128}+\dfrac{1}{256}-\dfrac{1}{2}-\dfrac{1}{4}-\dfrac{1}{8}-...-\dfrac{1}{256}-\dfrac{1}{512}\)

\(\Rightarrow A=1-\dfrac{1}{512}=\dfrac{511}{512}\)

Đặt ⇒2A=1+12+14+...+1128+1256⇒2A=1+12+14+...+1128+1256

⇒A=1−1512=511512

1/2 + 1/4 + 1/8 + 1/16 + ... + 1/256 + 1/512

= 256/512 + 128/512 + 64/512 + ... + 2/512 + 1/512

= 256 + 128 + 64 + .. + 2 + 1 / 512

= ???????

s=1/2+1/4+1/8+1/16+.....+1/256+1/512

sx2=(1/2+1/4+1/8+1/16+....+1/256+1/512)x2

sx2=1+1/2+1/4+1/8+......+1/126+1/256

sx2-s=(1+1/2+1/4+1/8+......+1/256)-(1/2+1/4+1/8+1/16++.....+1/256+1/512)

1+1/2+1/4+1/8+......+1/256-1/2-1/4-1/8-1/16-.....1/256-1/512

=1-1/512=511/512

có ai bik B=1/4+1/8+1/16+1/...+1/256 ko (nếu bik thì giải tử tế nhé mik cảm ơn)

Vậy dãy số đó là:

1/2 + 1/4 + 1/8 + 1/32 + 1/64 + 1/128 + 1/256 + 1/512 =

256/512 + 128/512 + 64/512 + 32/512 + 16/512 + 8/512 + 4/512 + 2/512 + 1/512 511/512

Đáp số: 511/512

A=1/2+1/4+1/8.....+1/256+1/512

2A=1+1/2+1/4+1/8...1/256

A=(1+1/2+1/4+1/8...1/256)-(1/2+1/4+1/8.....+1/256+1/512)

A=1-1/512

A=511/512

511/512

 Ta có: A =1/2+1/4+1/8+1/16+....+1/256+1/512 

=> 2A = 1 + 1/2 + 1/4 + 1/8 + ...+ 1/128 + 1/256

=> 2A - A = (1 + 1/2 + 1/4 + 1/8 + ...+ 1/128 + 1/256 -(1/2+1/4+1/8+1/16+....+1/256+1/512 )

         A =  1 - 1/512 = 511/512