Question

`x^2 = 9`

Answer 1

x=3

Answer 2

\(\left|x\right|=3\\ =>\left[{}\begin{matrix}x=-3\\x=3\end{matrix}\right.\)

Answer 3

\(x^2=9\)

\(\Rightarrow x^2=\left(\pm3\right)^2\)

\(\Rightarrow\left[{}\begin{matrix}x=3\\x=-3\end{matrix}\right.\)

 

Answer 4

`x^2 = 9`

`x^2 = (3)^2` hoặc `x^2 = (-3)^2`

`x = 3` hoặc `x = -3`