Question

\(\left(x+\dfrac{1}{3}\right)+\left(x+\dfrac{1}{9}\right)+\left(x+\dfrac{1}{27}\right)+\left(x+\dfrac{1}{81}\right)=\dfrac{56}{81}\)

Answer 1

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Answer 2

`(x+1/3)+(x+1/9)+(x+1/27)+(x+1/81)=56/81`

`x+x+x+x+1/3+1/9+1/27=56/81-1/81`

`4x+13/27=55/81`

`4x=55/81-13/27`

`4x=55/81-52/81`

`4x=16/81`

`x=4/108`

Vậy `x=4/108`