tính a=1/2.5+1/5.8+1/8.11…+1/2021.2024

0 bình luận về “tính a=1/2.5+1/5.8+1/8.11…+1/2021.2024”

1. `a=1/2.5+1/5.8+1/8.11…+1/2021.2024`

   `=>3a=3/2.5+3/5.8+3/8.11+…+3/2021.2024`

   `=>3a=1/2-1/5+1/5-1/8+1/8-1/11+…+1/2021-1/2024`

   `=>3a=1/2-1/2024`

   `=>3a=1011/2024`

   `=>a=337/2024`

    

   Bình luận

2. Đáp án:

   `A=1/(2.5)+1/(5.8)+….+1/(2021.2024)`

   `3A=3/(2.5)+3/(5.8)+…+3/(2021.2024)`

   `3A=1/2-1/5+1/5-1/8+…+1/2021-1/2024`

   `3A=1/2-1/2024`

   `3A=1011/2024`

   `A=1011/2024 : 3`

   `A=337/2024`

   Vậy `A=337/2024`

    

   Bình luận