Question

Answer 1

\(\left(x-\dfrac{2}{5}\right)^2=9\\ \left(x-\dfrac{2}{5}\right)^2=3^2\\ x-\dfrac{2}{5}=3\\ x=3+\dfrac{2}{5}\\ x=\dfrac{3.5+2}{5}\\ x=\dfrac{15+2}{5}\\ x=\dfrac{17}{5}\)

Answer 2

`(x-2/5)^2=9`

`(x-2/5)^2=3^2`

`x-2/5=3`

`x=3+2/5`

`x=15/5 + 2/5`

`x=(15+2)/5`

`x=17/5`

Vậy `x = 17/5`