rút gọn B = 1/2 + 1/2^3 + 1/2^5 + 1/2^7 + ... + 1/2^14

B = 1/2 + 1/2^3 + 1/2^5 + 1/2^7 + ... + 1/2^14

2B = 1 + 1/2^2 + 1/2^4 + 1/2^6 + ... + 1/2^13

2B - B = 1 + 1/2^2 + 1/2^4 + 1/2^6 + ... + 1/2^13 - 1/2 - 1/2^3 - 1/2^5 - 1/2^7 - ... - 1/2^14

B = 1 - 1/2^14

Vậy B = 1 - 1/2^14

XIN HAY NHẤT !

Giải thích các bước giải:

Ta có :

`B = 1/2 + 1/2^3 + 1/2^5 + 1/2^7 + ... + 1/2^14`

`2B = 1 + 1/2^2 + 1/2^4 + 1/2^6 + ... + 1/2^13`

`2B - B = 1 + 1/2^2 + 1/2^4 + 1/2^6 + ... + 1/2^13 - 1/2 - 1/2^3 - 1/2^5 - 1/2^7 - ... - 1/2^14`

`B = 1 - 1/2^14`