tính tổng a = 2 mũ 0 + 2 mũ 1 + 2 mũ 2 + chấm chấm chấm + 2 mũ 2006 Help me!!!!!!!!!!!!!! 11/07/2021 Bởi Ruby tính tổng a = 2 mũ 0 + 2 mũ 1 + 2 mũ 2 + chấm chấm chấm + 2 mũ 2006 Help me!!!!!!!!!!!!!!
`A = 2^0 + 2^1 + 2^2 + … + 2^2006` `=> 2A = 2^1 + 2^2 + 2^3 + … + 2^2007` `=> 2A – A = (2^1 + 2^2 + 2^3 + … + 2^2007) – (2^0 + 2^1 + 2^2 + … + 2^2006)` `=> A = 2^1 + 2^2 + 2^3 + … + 2^2007 – 2^0 – 2^1 – 2^2 – … – 2^2006` `=> A = 2^2007 – 2^0` `=> A = 2^2007 – 1` Vậy `A = 2^2007 – 1` Bình luận
`A=2^0+2^1+2^2+…+2^2006` `⇒2A=2^1+2^2+2^3+…+2^2006+2^2007` `-` `A=2^0+2^1+2^2+2^3+…+2^2006` ___________________________________________________ `⇒A=2^2007-2^0` `⇒A=2^2007-1` Bình luận
`A = 2^0 + 2^1 + 2^2 + … + 2^2006`
`=> 2A = 2^1 + 2^2 + 2^3 + … + 2^2007`
`=> 2A – A = (2^1 + 2^2 + 2^3 + … + 2^2007) – (2^0 + 2^1 + 2^2 + … + 2^2006)`
`=> A = 2^1 + 2^2 + 2^3 + … + 2^2007 – 2^0 – 2^1 – 2^2 – … – 2^2006`
`=> A = 2^2007 – 2^0`
`=> A = 2^2007 – 1`
Vậy `A = 2^2007 – 1`
`A=2^0+2^1+2^2+…+2^2006`
`⇒2A=2^1+2^2+2^3+…+2^2006+2^2007`
`-`
`A=2^0+2^1+2^2+2^3+…+2^2006`
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`⇒A=2^2007-2^0`
`⇒A=2^2007-1`