Tính nhanh: A = `1/1.2+1/3.4+1/5.6 +…..+ 1/59.60` 04/11/2021 Bởi Amaya Tính nhanh: A = `1/1.2+1/3.4+1/5.6 +…..+ 1/59.60`
`A=1/(1.2)+1/(3.4)+1/(5.6)+….+1/(59.60)`$\\$`⇒A=1-1/2+1/3-1/4+1/5-1/6+…+1/59-1/60`$\\$`⇒A=(1+1/3+1/5+…+1/59)-(1/2+1/4+1/6+…+1/60)`$\\$`⇒A=(1+1/2+1/3+1/4+1/5+…+1/59)-2.(1/2+1/4+1/6+…+1/60)`$\\$`⇒A=1/31+1/32+…+1/60` Bình luận
Đáp án: `↓↓` Giải thích các bước giải: `A=1/(1.2)+1/(3.4)+1/(5.6)+….+1/(59.60)` `=1-1/2+1/3-1/4+1/5-1/6+…+1/59-1/60` `=(1+1/3+1/5+…+1/59)-(1/2+1/4+1/6+…+1/60)` `=(1+1/2+1/3+1/4+1/5+…+1/59)-2.(1/2+1/4+1/6+…+1/60)` `=1/31+1/32+…+1/60` Bình luận
`A=1/(1.2)+1/(3.4)+1/(5.6)+….+1/(59.60)`$\\$`⇒A=1-1/2+1/3-1/4+1/5-1/6+…+1/59-1/60`$\\$`⇒A=(1+1/3+1/5+…+1/59)-(1/2+1/4+1/6+…+1/60)`$\\$`⇒A=(1+1/2+1/3+1/4+1/5+…+1/59)-2.(1/2+1/4+1/6+…+1/60)`$\\$`⇒A=1/31+1/32+…+1/60`
Đáp án:
`↓↓`
Giải thích các bước giải:
`A=1/(1.2)+1/(3.4)+1/(5.6)+….+1/(59.60)`
`=1-1/2+1/3-1/4+1/5-1/6+…+1/59-1/60`
`=(1+1/3+1/5+…+1/59)-(1/2+1/4+1/6+…+1/60)`
`=(1+1/2+1/3+1/4+1/5+…+1/59)-2.(1/2+1/4+1/6+…+1/60)`
`=1/31+1/32+…+1/60`