Toán tinh nhanh 1+1/2+1/4+1/8+1/16+1/32+1/64+1/128+1/256 22/07/2021 By Liliana tinh nhanh 1+1/2+1/4+1/8+1/16+1/32+1/64+1/128+1/256
`A=1+1/2+1/4+1/8+1/16+……+1/256` `⇒2A=2+1+1/2+1/4+……..+1/128` `⇒2A-A=(2+1+1/2+1/4+…….+1/128)-(1+1/2+1/4+……..+1/256)` `⇒A=2-1/256=511/256` Trả lời
`A=1+1/2+1/4+1/8+………+1/256` `2A=2+1+1/2+…….+1/128` `2A-A=(2+1+1/2+…….+1/128)-(1+1/2+……..+1/256)` `A=2-1/256=511/256` Trả lời
`A=1+1/2+1/4+1/8+1/16+……+1/256`
`⇒2A=2+1+1/2+1/4+……..+1/128`
`⇒2A-A=(2+1+1/2+1/4+…….+1/128)-(1+1/2+1/4+……..+1/256)`
`⇒A=2-1/256=511/256`
`A=1+1/2+1/4+1/8+………+1/256`
`2A=2+1+1/2+…….+1/128`
`2A-A=(2+1+1/2+…….+1/128)-(1+1/2+……..+1/256)`
`A=2-1/256=511/256`