Tính: 1/1.3 + 1/3.5 + 1/5.7 +…+ 1/2009.2001 Mng ơi giúp em vs ạ em camon!!!! 10/11/2021 Bởi Piper Tính: 1/1.3 + 1/3.5 + 1/5.7 +…+ 1/2009.2001 Mng ơi giúp em vs ạ em camon!!!!
`1/(1.3) + 1/(3.5) + 1/(5.7) +…+ 1/(2009.2011)` `=1/2 ( 1/(1.3) + 1/(3.5) + 1/(5.7) +…+ 1/(2009.2011)` `=1/2(1/1 – 1/3 + 1/3 – 1/5 + 1/5 – 1/7 +…+ 1/2009 – 1/2011)` `=1/2 (1/1 – 1/2011)` `=1/2 . 2010/2011` `= 1005/2011` #TEAM_IQ_2000 Bình luận
Đáp án: `=1005/2011` Giải thích các bước giải: Có: `1/1.3 + 1/3.5 + 1/5.7 +…+ 1/2009.2011` `=1/2(2/1.3 + 2/3.5 + 2/5.7 +…+ 2/2009.2011)` `=1/2(1-1/3+1/3-1/5+1/5-1/7+…+1/2009-1/2011)` `=1/2(1-1/2011)` `=1/2. 2010/2011` `=1005/2011` Bình luận
`1/(1.3) + 1/(3.5) + 1/(5.7) +…+ 1/(2009.2011)`
`=1/2 ( 1/(1.3) + 1/(3.5) + 1/(5.7) +…+ 1/(2009.2011)`
`=1/2(1/1 – 1/3 + 1/3 – 1/5 + 1/5 – 1/7 +…+ 1/2009 – 1/2011)`
`=1/2 (1/1 – 1/2011)`
`=1/2 . 2010/2011`
`= 1005/2011`
#TEAM_IQ_2000
Đáp án:
`=1005/2011`
Giải thích các bước giải:
Có:
`1/1.3 + 1/3.5 + 1/5.7 +…+ 1/2009.2011`
`=1/2(2/1.3 + 2/3.5 + 2/5.7 +…+ 2/2009.2011)`
`=1/2(1-1/3+1/3-1/5+1/5-1/7+…+1/2009-1/2011)`
`=1/2(1-1/2011)`
`=1/2. 2010/2011`
`=1005/2011`