Question

tìm x

(X+2/9)^2=4/81

Answer 1

\(\left(x+\dfrac{2}{9}\right)^2=\dfrac{4}{81}\\ \left(x+\dfrac{2}{9}\right)^2=\left(\dfrac{2}{9}\right)^2\\ x+\dfrac{2}{9}=\dfrac{2}{9}\\ x=\dfrac{2}{9}-\dfrac{2}{9}\\ x=0\)

Answer 2

Mình bổ sung thêm TH2 nữa. 

\(\left(x+\dfrac{2}{9}\right)^2=\left(-\dfrac{2}{9}\right)^2\\ x+\dfrac{2}{9}=-\dfrac{2}{9}\\ x=-\dfrac{2}{9}-\dfrac{2}{9}\\ x=-\dfrac{4}{9}\)

Answer 3

\(...\Rightarrow\left(x+\dfrac{2}{9}\right)^2=\left(\dfrac{2}{9}\right)^2\)

\(\Rightarrow x+\dfrac{2}{9}=\dfrac{2}{9}\Rightarrow x=0\)