Answer
{$\dfrac{-2+\sqrt{7}}{5},\dfrac{-2-\sqrt{7}}{5}$}
Work Step by Step
Given: $(x+\dfrac{2}{5})^2=\dfrac{7}{25}$
Apply The Square Root Property.
This can be written as: $(x+\dfrac{2}{5})=\sqrt{\dfrac{7}{25}}$
or, $(x+\dfrac{2}{5})=\pm \dfrac{\sqrt{7}}{5}$
or, $x=-\dfrac{2}{5}+\dfrac{\sqrt{7}}{5},-\dfrac{2}{5}-\dfrac{\sqrt{7}}{5}$
Hence, solution set is $x=${$\dfrac{-2+\sqrt{7}}{5},\dfrac{-2-\sqrt{7}}{5}$}