e) (1 - 1/2) . (1 - 1/3 ) . (1 - 1/4) . (1-1/5) . .... . (1 - 1/19) . (1 - 1/20)

Question

phuongthao · Answer

( `1` `-` `1/2` ) `.` ( `1` `-` `1/3` ) `.` … ( `1` – `1/19` ) . ( `1` `-` `1/20` )

`=` ( `2/2` `-` `1/2` ) `.` ( `3/3` `-` `1/3` ) `.` … ( `19/19` – `1/19` ) . ( `20/20` `-` `1/20` )

`=` `1/2` . `2/3` . … . `18/19` . `19/20`

`=` `1/20`

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ngocdiep · Answer

Đ&aacute;p &aacute;n:       Giải th&iacute;ch c&aacute;c bước giải:   `(1 - 1/2) . (1 - 1/3 ) . (1 - 1/4) . (1-1/5) . .... . (1 - 1/19) . (1 - 1/20)`   `=1/2.2/3.3/4.4/5......19/20   =1.2.3.4.5....19/2.3.4.5...20=1/20

e) (1 – 1/2) . (1 – 1/3 ) . (1 – 1/4) . (1-1/5) . …. . (1 – 1/19) . (1 – 1/20)

0 bình luận về “e) (1 – 1/2) . (1 – 1/3 ) . (1 – 1/4) . (1-1/5) . …. . (1 – 1/19) . (1 – 1/20)”

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