Question

1 phần 3 + âm 1 phần 4 + 1 phần 5 + âm 1 phần 6 + 1 phần 7 + 1 phần 6 +1 phần âm 5 + 1 phần 4 + 1 phần âm 3 

Answer 1

`1/3+ -1/4+1/5+ -1/6+1/7+1/6+1/(-5)+1/4+ -1/3`

`=(1/3-1/3)+(1/4-1/4)+(1/5-1/5)+(1/6-1/6)+1/7`

`=0+0+0+0+1/7`

`=1/7`

Answer 2

Answer 3

gấp ạ

Answer 4

Ta có: \(\dfrac{1}{3}+\dfrac{-1}{4}+\dfrac{1}{5}+\dfrac{-1}{6}+\dfrac{1}{7}+\dfrac{1}{6}+\dfrac{1}{-5}+\dfrac{1}{4}+\dfrac{1}{-3}\)

\(=\left(\dfrac{1}{3}+\dfrac{1}{-3}\right)+\left(\dfrac{-1}{4}+\dfrac{1}{4}\right)+\left(\dfrac{1}{5}+\dfrac{1}{-5}\right)+\left(-\dfrac{1}{6}+\dfrac{1}{6}\right)+\dfrac{1}{7}\)

\(=0+0+0+0+\dfrac{1}{7}\)

\(=\dfrac{1}{7}\)

Answer 5

-2 phần 5 12 phần X